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Class Notes - Class #14

 The next several mitzvot, mitzvot #244 – 247, bring us back to agricultural matters.  Mitzvah #244 prohibits breeding two different species of animals, and mitzvah #245 prohibits sowing a field with two types of plants.  (There is a parallel mitzvah related to vineyards that we will see later in our study.)

            These two mitzvot are closely related and our author says they share a shoresh.  According to the author, who is echoing the creation story in Genesis, when God created the world He created many distinct types of creatures, each specifically designed to fit a particular purpose. Each species was instructed by God to reproduce “after its own kind.”  Thus, if we mate animals that do not naturally mate with each other we are foiling God’s perfect plan.

            The Torah says God found His creation to be “very good.”  The author cautions us from thinking we really understand what that means.  God’s acts of creating are per se perfect; God does not have to look back at His creation to see if it need touching up the way a human craftsman would.  But the Torah can only communicate with people by using analogies that people can understand.

            The author also recalls his earlier discussion of the shoresh of the mitzvah to kill witches and sorcerers.  (See mitzvah #62.  We will see several more related mitzvot shortly.)  There the author imagines each of God’s creations having a certain nature and role.  God sets a watchful force over each creation to keep it on track.  When interbreeding mixes those separate creations, the role of those forces is temporarily thwarted and God’s perfect plan is foiled.

            These various concepts seem at odds with modern scientific theory about evolution.  We cannot know if our author would have understood the shoreshim of these mitzvot differently in light of those scientific advances.

Although the author gives us some information about how to tell which animals are of different species and which plants may be planted in the same field, he does not give us enough information to formulate a rule.  He is reflecting earlier sources.  The Mishnah, in Kilayim, gives lists of animals that may not be mated and plants that may not be planted together. Formulating a conceptual rule is very difficult. 

            Someone violates mitzvah #244 by mating any two animals that are not the same species. It applies to all animals: domestic animals, wild animals, mammals, bird, even sea creatures.  It does not matter who owns the animals. Parallel to the definition we saw when we discussed forbidden sexual relations, someone violates this mitzvah by physically facilitating penetration. The person who physically facilitates the penetration is punishable by malkos. We may not recruit a non-Jew to facilitate the copulation on our behalf.  But we are permitted to benefit from the offspring of the forbidden husbandry, and even eat the offspring if the parents were both animals we are permitted to eat.

It is fine to leave two animals of different species in the same enclosure in the hope the animals will mate on their own.  But apparently if someone does more than that to encourage the animals to mate, or if someone brings them together without actually facilitating the copulation, the person violates a rabbinic prohibition.  (See the final sentence of this mitzvah/essay.)

The author describes a disagreement about the status of the offspring.  According to Rabbi Isaac alFasi, (referred to by the acronym “Rif,”) the offspring is considered to be of the same species as the mother animal.  According to other authorities, however, the Talmud’s discussion of whether we also consider the father in determining the species of the offspring does not eliminate the possibility that the father also counts, we should be strict and consider both parents in determining the species of the offspring.  Later we will see a mitzvah prohibiting us from yoking two animals of different species together and then plowing with them.  For that mitzvah, the author says, we consider the offspring to be the same species as its mother.  That seems consistent with Rif’s opinion.  But we will also see a mitzvah prohibiting us from slaughtering an animal and its offspring on the same day.  For that mitzvah, if we know the offspring’s father then the mitzvah applies to slaughtering the father and his offspring on the same day.  That seems consistent with the opinion of the other authorities. The species of the offspring matters for this mitzvah as well, since it governs which animals we may mate with the offspring animal. 

This prohibition applies everywhere and at all times.

Mitzvah #245 applies to plants, and seems conceptually similar to the prior mitzvah.  But it applies only in Israel and only on land owned by one person.  (If one farmer plants one crop right up to the property line and the adjoining farmer plants a different crop right up to the other side of the property line so the two different crops are right next to each other, that is fine.)  It applies to food crops but not to other crops.  We are forbidden to plant two species together, to weed them if they were planted together, or to cover the roots with earth by hand or with a tool.  This applies to plants in the ground or in pots that have perforations in the bottom; planting in pots with perforations in the bottom is considered analogous to planting in the ground because the roots could extend through the holes and into the ground.  At the beginning of the month of Adar the authorities would remind people of this mitzvah as they were reminding people of the half-shekel owed to the Temple.  In early spring, farmers can easily weed out their fields to conform to this mitzvah and then keep them that way throughout the growing season.

This mitzvah also applies to trees, but in a different way:  it prohibits grafting one species of tree onto the stock of a different species of tree, or grafting one species of plant onto the stock of any other species of plant.  This prohibition on grafting applies everywhere, not just in Israel.  It is fine to plant trees of different species next to each other.

Someone who plants two species of plant adjacent to each other or who grafts one species of tree onto the stock of another species of tree is punishable.  But, as we saw in the prior mitzvah, it is permissible to keep and use the yield of forbidden plantings and grafts.

The author discusses two aspects of the prohibition on planting two species of food plants together.  First, he considers what happens when seeds of two species get mixed together.  The rule seems parallel to the concept of bitul we have seen elsewhere.  A farmer may plant the mixture of wheat and barley seeds if the proportion of one type of seed is less than one part in 24 of the other kind of seed.  If the proportion is higher, the farmer must pick out some of the minority type of seed or add more of the majority type of seed.

Second, the author gives us the geometry puzzles that are part of applying this mitzvah.  The two species must be planted far enough apart so that one species does not derive sustenance from the other (I am not sure how the rabbis thought plants were nourished.)  The rabbis gave a rule for implementing that principle practically:  the farmer must leave 1.5 t’fachim, about 6 inches, as a border around each type of plant.  So in order to plant two species near each other, each getting 1.5 t’fachim as a border, each species of plant will actually be 3 t’fachim, about 12 inches, from another species of plant.  That will normally prevent the two species of plant from appearing intertwined with each other.   That border is fine even if the leaves of the two species overlap a little.  But if the two species do appear intertwined, the farmer must increase the size of the separation border. 

First the author says a farmer could plant five different species of plants in a garden bed 6 x 6 t’fachim.  The farmer could plant one species of plant in a 1.5 x 1.5 box in each corner of the garden bed, and then plant another species in a 3 x 3 box in the center.  The plants in each corner box would be 3 t’fachim from each other box.  Plant beds that touch at the corner are not a problem. So there is enough space between each species of plant.

Puzzle #2:  Actually, the farmer could plant nine different species in one 6 x 6 garden plot.  How?  This time we need to think of one individual plant of each species.  The farmer can plant one plant in each corner, one plant in the middle, and one plant at the midpoint of each side of the plot.  The plants along the edges are 3 t’fachim from each other.  The plant in the center is 3 t’fachim from the plants at the center of each side, and even farther from the plants in each corner.  Again, there is enough border space between each plant.

Puzzle #3:  Why does the Jerusalem Talmud say the farmer can only plant five species rather than nine?  The author says this imagines a series of adjoining garden beds.  If the farmer staggers them so that the blank in each side of one bed is up against plants at the corner of the adjacent bed, the combined garden beds create a sort of zigzag line, each 6 x 6 section holding five species of plants.

The author presents these puzzles and does not give solutions.  The solutions I suggest above may or may not be what the author had in mind.  But pedagogically the author is challenging the reader to try to figure out how to solve these puzzles.  One can imagine the author’s son and his friends taking up the challenge until they figure it out.


Mitzvot #246 and 247 regulate our use of tree fruit in the first four years of the tree’s life.  Mitzvah #246 prohibits our eating the fruit a tree produces during the first three years of its life.  Mitzvah #247 requires us to take the fourth year harvest to Jerusalem and eat it there.

The fruit a tree produces during its first three years of life is called “orlah” and we are forbidden to eat that fruit if the person planting the tree intended the tree to produce fruit for eating.  If the person planting the tree planted it for another purpose, such as for wood or as a barrier, and did not intend to eat the fruit, then we may eat any fruit that happens to grow on that tree.  If the planter had mixed intentions, thought, the fruit is orlah.   The prohibition on eating the orlah fruit includes the fruit and any shell that stays on the fruit if  removing the shell while the fruit is growing would damage the fruit.

The author says this mitzvah applies everywhere.  That is a bit puzzling since the source verse, Lev. 19:23 says, “when you come into the land,” so it seems the mitzvah should apply only in Israel.  The author cites Rambam, who says the fact that this prohibition applies everywhere is “halachah l’mosheh misinai.”

The author also explains a way in which this mitzvah deviates from a general principle of how most mitzvot are applied.  In general, when there is doubt about whether a Torah prohibition applies to a particular case, we choose to be strict.  But when there is doubt about whether a rabbinic prohibition applies to a particular case, we choose to be lenient.  That rule should apply equally to prohibitions mentioned explicitly in the Torah and also to prohibitions that are halachah l’mosheh misinai.  As to orlah, though, even though it is a Torah requirement, we decide doubtful cases leniently.  The author says that deviation from the normal rule is part of the received halachah l’mosheh misinai.  For example, let’s say my neighbor is eating a fruit from a tree in my backyard.  It happens to be that the tree is young and the fruit is orlah.  But the neighbor does not know for sure whether or not the fruit is orlah.  My neighbor is allowed to eat the fruit, and I am not required to tell my neighbor that the fruit is orlah even though orlah is a Torah prohibition.

The source verse for mitzvah #248 is Lev. 19: 24, which says that the fruit of a four-year-old tree is “holy for giving praise to God.”  The rabbis understand that to mean that the owner of the tree should harvest the fruit of a four-year-old tree, take the fruit to Jerusalem and eat it there.  That fruit is called “neta r’va’i.” 

The author offers several different approaches to the shoresh of this mitzvah. (He discusses the shoresh for mitzvah #247 and #248 together.)  First he cites the Rambam, who sees this mitzvah as analogous to bikkurim, the first of the harvest that we learned about in mitzvah #91.  The neta r’va’i is likely the first significant harvest from a tree; the tree usually bears little fruit in the first three years, and what it does bear is likely of poor quality.  (The author cites medieval scientific theory for the proposition that eating the fruit of the first three years might even be harmful.)  When the farmer harvests the neta r’va’i, the farmer should express gratitude to God.  That way, the farmer and his or her produce will be blessed. 

The similarity between neta r’va’i and ma’aser sheni lead the author to a different approach to the shoresh.  Most people grew their own food, so most people ended up with food they were required to eat in Jerusalem.  That would be more convenient and efficient if the farmer has a relative living in Jerusalem.  The farmer could come to visit, bringing food for everyone, and have a place to stay.  While there, the farmer could study Torah in Jerusalem, the center of Torah study.

We will see later in our study the agricultural tax called “ma’aser sheni,” “the second tithe.”   Neta r’va’i and ma’aser sheni have a lot in common, and our author explains some of the parallels in this essay.  According to the author, neta r’va’i and ma’aser sheni are similar in several ways:

  1. If it is hard for the farmer to take the food to Jerusalem, the farmer can redeem the food for money, take the money to Jerusalem, buy food there and eat it there.  The author describes the words the farmer should recite in the process of redeeming the fruit.  The farmer may eat the redeemed food anywhere once it has been redeemed for money. 
    1. Lev. 27:31 says that a farmer who redeems ma’aser must add on 1/5 the value of the food.  We saw earlier that halachic sources express fractions in terms of the total with the fraction added rather than in terms of the original amount, so the 1/5th in the source verse would be what we would call ¼ of the original amount.  The farmer brings 125% of the value of the neta r’va’i or ma’aser sheni to Jerusalem to buy food.  (No such additional amount is added if one person uses his or her own money to redeem someone else’s neta r’va’i.)
    2. Actually, if the farmer redeems the neta r’va’i for less than the required amount of money, the redemption is effective as long as the farmer redeems it for at least a prutah.  Presumably the farmer is still required to make up the difference.
  2. The produce has to reach a certain point of ripening before the obligations of neta r’va’i and ma’aser sheni apply.  The fruit has to reach at least 1/3 of its anticipated growth.
  3. The author describes a disagreement about whether the fruit can be redeemed while it is still on the tree or only after it has been harvested.  Rambam thinks only harvested fruit can be redeemed, but others think the fruit can be redeemed while it is still on the tree.
  4. The farmer can give fruit as a gift to someone else while the fruit is on the tree and before it has reached 1/3 or its anticipated growth, but not after that.
  5. Grapes may be redeemed while they are still grapes or after they have been made into wine.  Olives may be redeemed while they are still olives or after they have been made into olive oil.  Other fruits must be redeemed while they are still in the same state as when they were picked.
  6. In an orchard of four-year-old trees, the farmer need not leave the parts of the harvest normally left for poor people.  The farmer need not separate other agricultural taxes from the neta r’va’i, either.
  7. We will see later that defining the boundaries of Israel is a complicated enterprise.  The rabbis extended the reach of some agricultural taxes beyond the borders of Israel and into parts of Syria.  They were afraid that Jews would be motivated to move outside of Israel and into the suburbs if the suburbs had lower tax requirements.  But they did not extend ma’aser sheni or neta r’va’i to Syria. 


The author describes two different opinions about when and where this mitzvah applies.  (Recall that the mitzvah of orlah applies everywhere and at all times.)  Rambam thinks neta r’va’i applies only in Israel and only when the Temple functioned.  So this mitzvah does not apply now either in Israel or elsewhere.

 Other authorities think that neta r’va’i applies in Israel at all times, not only when the Temple is functioning.  They also think that the rabbis apply this mitzvah to four-year-old grape vines everywhere. But if the Temple is not functioning this mitzvah works differently.  The farmer should not take the food to Jerusalem and eat it there, or redeem it and use the money to buy food in Jerusalem.  Rather, the farmer should redeem the neta r’va’i for the minimum possible amount and say the brachah on that act of redemption.  Then the farmer should destroy the redemption money, for example by throwing it into the Dead Sea.  The money must be destroyed carefully lest someone else mistakenly find the money and use it for something else. 


Mitzvah #248 is an example of a “lav sheb’chlalut,” one negative mitzvah that includes many different prohibitions.  One prohibition under this mitzvah is the case of the “stubborn and rebellious son,” and our author discusses that at length.  We will start with the other applications, and then return to that.

            The source verse for this mitzvah is Lev. 19:26, which says, “Lo tochlu al hadam,”  “do not eat on/with the blood.”  This is different from the mitzvah not to eat blood that we saw earlier.  (See mitzvah #148.) It is not easy to make sense of the words of this verse.  But the rabbis find several situations that seem to fit:

  1. Eating part of an animal while the animal is still alive. 
  2. Eating parts of animal sacrifices before the blood has been sprinkled on the altar in the required way.
  3. The judges on a court that decides to impose a death penalty may not eat on the day the penalty is carried out.
  4. Normally, when someone dies, members of the community prepare the first meal the mourners eat after the burial. That is called the “meal of consolation.” No meal of consolation is prepared for the family of someone executed by the court.
  5. This prohibits someone from eating on any given day before praying.


            The rabbis use this verse to fill a legal gap on another topic and our author sees this as the primary meaning of the verse.  Deut. 21:18 – 21 describes a “stubborn and rebellious son.”  It describes a son who steals, eats too much, drinks too much, and is generally headed for trouble.  His parents bring him to court and if the court decides the son fits the requirements, the son is subject to death by stoning.   The Encyclopedia Judaica suggests that in the Biblical period this may have been a limitation on a father’s ability to do violence to a misbehaving child.  Under the Biblical requirements, the child’s mother and a court have to agree.

Under more modern conditions, though, this is a troubling passage. The son is punished without having done anything terrible wrong, and the person being executed is an adolescent.  We should not be surprised that the rabbis read the source verses very carefully to determine when this rubric applies. Our author lists some of the requirements:

This rubric applies to sons and not to daughters.  It does not apply to those of ambiguous gender. 

The son must be old enough to have two pubic hairs, but young enough so that public hair has not completely surrounded his penis.  That is a period of at most three months.

The son must steal from his father and use the money to buy meat and wine cheaply.

The son must consume the meat and wine outside his father’s premises in the company of lowlife companions.

The son must eat the meat partly cooked the way thieves do and drink the wine before it is fully mixed the way drunkards do.

The son must eat the meat in one huge bite and drink the wine in one huge gulp.

 The son must eat only meat and drink only wine during the offending meal.

The son must eat and drink without violating any other mitzvot.  The food must be kosher and the meal cannot take place on a day when the son is required to fast, even if the fast is prescribed by the rabbis rather than by the Torah.  The source verse says the son is punishable if he disobeys the voice of his parents, so if the son is violating the Torah his case does not fit the requirements.

Both the father and mother have to bring the son to court and accuse him.  If either parent refuses, the son is off the hook.

If either parent is lame, blind, deaf, mute or one-handed, the son is off the hook.  The parents must “take hold of him,” so they need to have both hands.  They must “take him out,” so they cannot be lame.  They must make an accusation in court, so they cannot be mute.  They have to identify the son as theirs, so they cannot be blind.  They must attest that the son has not listened to their warnings, so they cannot be deaf.

The author also mentions that there are specific requirements for how the son is warned, and that witnesses have to see parts of the process, although he does not go into detail.

All of this has to happen twice.  The first time, the son is subject to malkos.  He is subject to the death penalty only if he does it again.


As the author points out, the rabbis are going out of their way to restrict the possibility of a rebellious son ever being executed.  The Talmud says this death penalty was never carried out, although one rabbi claims to have seen it instituted once. 

Where the Torah mandates the death penalty, the rabbis insist on finding a different verse that prohibits the punishable behavior.  Deuteronomy is clear that the stubborn and rebellious son is subject to the death penalty, but there is no obvious prohibition verse.  The source verse for this mitzvah is used to fill that gap. The verse fits because the behavior of the stubborn and rebellious son leads to bloodshed in the form of the death penalty. 

But getting it to fill that gap is difficult, and our author explains how Rambam makes it work and why Ramban is not satisfied. The rebellious son is punishable first with malkos and then with death by stoning.   There is no obvious source verse for either punishment.  In fact, there is no obvious punishment verse to justify the malkos either.

The source verse for this mitzvah is considered the prohibition verse that serves as the basis for the death penalty.   Both Rambam and Ramban agree that a lav sheb’chlalut prohibits behavior but does not support any punishment. Rambam thinks that there is an exception to that rule: where the Torah imposes karet or the death penalty the prohibition can be in a lav sheb’chlalut.  Ramban disagrees, and would require the prohibition verse to be specific to the behavior subject to the death penalty.

Both the prohibition and penalty of malkos for the rebellious son are derived through g’zerah shavah.  The prohibition is derived from the common phrase “vayitru oto,” “and they chastise him” in the Deut. 21:18 about the rebellious son and in Deut. 22:18 about a man who ruins his wife’s good reputation.  The punishment of malkos is derived from the word “ben” in Deut. 21:18 describing the rebellious son and the word “bin” in Deut. 25:2 describing the court administering malkos.  Those two words consist of the same letters although they are vocalized differently and mean different things.  Neither of these verbal comparisons seems closely related to the plain meanings of the Biblical text.

That still leaves Rambam with a problem; normally, according to Rambam, a g’zerah shavah cannot be the basis of punishment. The author does not explain how Rambam answers this objection.

The author focuses on the case of the rebellious son in discussing the shoresh of this mitzvah.  The author says overeating and drinking liquor is the source of all sorts of problems for people.  When people are satisfied and feel secure they tend to get into trouble.  They tend to focus more on the material and less on the spiritual.  This is especially dangerous to young people who are first learning to control their appetites.  Since eating is something we all have to do, it is a hard lesson to learn.  People would be better off if they had just enough to eat to keep them alive.  The institution of the rebellious son serves as a reminder to all of us to keep ourselves from overindulgence and the threats of abundance. 

Our author seems to back off from discussing the obvious moral questions about the rebellious son.  The final Mishnah discussing this issue, Sanhedrin 8:5  says that the rebellious son is “judged because of his end.” The pattern of behavior of the rebellious son shows that, if  he is allowed to continue, his behavior will deteriorate and he and his community will all be worse off.  That is a very problematic assertion, and the rabbis were well aware of the moral problems.  Our author does not deal with this at all, and that seems uncharacteristic of him.