Sefer HaChinuch ספר החינוך

To not sow seeds of forbidden mixtures and not graft in any place in the Land: To not sow two species of seed, such as wheat and barley or fava beans and peas, together — only in the Land of Israel — as it is stated (Leviticus 19:19), “your field shall you not sow [with] a forbidden mixture.” And the explanation comes about it (Kiddushin 39a) that the verse is speaking about a field that we have in the Land.

I have written what I have known from the roots of the commandment on the preceding commandment, and likewise on the commandment of a witch in the Order of Mishpatim (Sefer HaChinukh 62).

From the laws of the commandment is that which they, may their memory be blessed, said (Moed Katan 2b) that it is one whether one sows or weeds or covers with dirt — they are all included in sowing, to be lashed for them. And whether he covered [the seeds] with his hand, with his foot or even with a tool — he is lashed for all of them. And one who sows them in a holed pot, is like he sows in the actual ground (Mishnah Kilayim 7:8). And that which they said (Talmud Yerushalmi Kilayim 1:1) that there is only a prohibition on account of forbidden mixtures of seeds with seeds that are fitting for human food. But the bitter seeds — even those that are capable of healing people — do not have [the prohibition] of forbidden mixtures of seeds. And behold, forbidden mixtures of trees are included in this negative commandment of “your field shall you not sow [with] a forbidden mixture.” However the prohibition of forbidden mixtures of trees is only by way of grafting — for example, that he grafted a sprig of an apple tree to a citron (etrog) tree, and all that is similar to it, that are two species. But by way of sowing — for example, to sow the seed of a tree with [other] seeds — this thing is permissible even from the outset; except for the vineyard, as we will explain in the Order of Ki Tetseh (Sefer HaChinukh 549), with God’s help.

And they, may their memory be blessed, said (Mishnah Kilayim 8:1) that even though there is lashes for both one who sows seeds of a forbidden mixture and one who grafts trees of a forbidden mixture — behold, they are permitted to be eaten; as it is only their planting that was forbidden. And so [too,] they permitted planting a sprig of a tree that was grafted with a forbidden mixture, and to plant a seed that was sowed in a forbidden mixture. And seeds are divided into three groups and three names and these are them: grains, legumes and garden seeds — and there are some of the garden seeds that are called types of vegetables. And even though it was forbidden to us to mix two types of seeds even if they are of one name — for example, wheat with barley, in that both of them are called grain; and so [too,] fava beans and peas, even though both of them are called legumes — nonetheless, there is a small distinction between them in the difference of the name. How is this? That if one part of wheat bigger than the twenty-three [individual] parts of barley was mixed unintentionally, there is no need to separate it out; less than this, he must separate it. But if it was from the garden seeds that was mixed, its measure is one in twenty-four of that which we plant from that type of garden seed in [a field, the measure of which is] a beit seah. And grain and legumes are like one species concerning this, and their measurement is one part in twenty-four of grain [regardless of how much of that type is planted in a field]. And they, may their memory be blessed, said (Mishnah Shekalim 1:1) that we announce about the shekalim and forbidden mixtures on the first of Adar; and everyone goes out to his garden and to his field, and cleans it from [these mixtures]. And everything that is two species, even though they are similar in their shape, are forbidden on account of forbidden mixtures. And everything that is one species, even though their shapes are different because of the variation of location or the variation in the work on the land — behold, it is like one species.

And the laws of the measure of distancing needed between two species are many (Mishnah Kilayim 2:10). And they, may their memory be blessed, said (Rashi s.v. vaechat be’emtsa on Shabbat 84b) that the measure of distancing of two species of vegetables such that they not feed one from the other is a handbreadth and a half for each one, such that it comes out that the gap [between] the two of them is three handbreadths. And that which they said in Mishnah Kilayim 3:1 — and it was also brought in Shabbat in the chapter [entitled] Amar Rabbi Akiva (Mishnah Shabbat 9:2) — that we plant five [types] of seeds in a garden bed that is six handbreadths by six handbreadths. And that, which according to our words, they should have said nine — eight on the four sides and one in the middle — is not difficult; as they already resolved it in the Talmud Yerushalmi Shabbat 9:2), that [the Mishnah] was learned about a garden bed [surrounded by other] garden beds.

And the principle that comes out in our hands from their words, may their memory be blessed, regarding forbidden mixtures of seeds is that anytime that there is a proper distance between the two types — and that is one-and-a-half handbreadths, as we said — even if the leaves are mixed up, we do not concern ourselves about them; and likewise, anytime they appear separated one from the other, such that the leaves of one garden bed lean to one side and the leaves of the garden bed adjacent to it [lean] to another side — even though they are feeding one from the other — we do not concern ourselves with their feeding. As the Torah [only] paid heed to both of them together — that they feed one from the other and that their feeding be seen clearly by the eyes of the onlookers. And about what are these words speaking, that it needs distancing, or something that separates? When he sowed in his [own] field. But if his field is planted with wheat, it is permitted for his fellow to sow barley adjacent to it; as it is stated, “your field shall you not sow [with] a forbidden mixture” — meaning to say, specifically, your field — as it was not written, “the land shall you not sow [with] a forbidden mixture.” And they, may their memory be blessed, also learned (Kiddushin 39a) [from] “your field,” to say that it is only in the Land that the prohibition of forbidden mixtures of seeds is practiced, but not outside of the Land. [This is the case,] even though they did not say thus regarding the grafting of trees, which is also derived from “your field,” but which is rather practiced in every place — and as Shmuel said [there] in the first chapter of Kiddushin, since he compares the grafting of trees to the mating of beasts which is practiced in every place. They, may their memory be blessed, have already resolved [this difficulty] there in Kiddushin. And if you desire, my son, to know [their resolution], see it there. And the rest of its details are in Tractate Kilayim.

And the prohibition of forbidden mixtures of seeds is practiced by males and females only in the Land of Israel, as we said. But outside of the Land, it is permitted to mix seeds from the outset and to sow them. And even in the Land, the prohibition is only on an Israelite, but it is permitted to say to a gentile to sow a forbidden mixture for him. Nonetheless, it is forbidden for [the Israelite] to maintain them in his field once they grow. And all that we have said is specifically with forbidden mixtures of seeds. But forbidden mixtures of trees — meaning to say, the grafting which is forbidden with them — is practiced even outside the Land, as we said; and it is forbidden for an Israelite to allow a gentile to graft his tree, even outside of the Land. And one who transgresses this — whether a man or a woman — and sows forbidden mixtures of seeds in the Land of Israel is liable for lashes. And one who grafts a tree to a tree that is not its species, or a vegetable with a tree or a tree with a vegetable — even outside of the Land, and all the more so in the Land — is also liable for lashes.