Sefer HaChinuch ספר החינוך

To not slaughter a beast and its child on one day: That we not slaughter a beast and its child on one day — whether consecrated or mundane — as it is written (Leviticus 22:28), “it and its child you shall not slaughter on one day.”

It is from the roots of the commandment that a person should place upon his heart that the providence of God, blessed be He, is upon all species of animals more generally. And with His providence over them, they shall endure eternally; as His providence over things is [itself] their sustenance. And therefore no species will ever become completely extinct. And even though His providence over the human species is individual — and as I explained earlier in the Order of Eesha ki Tazria (Sefer HaChinukh 169) — this is not the case for other species of animals. Rather His providence, blessed be He, is for the species as a whole. And we are therefore prevented from finishing ‘the tree and its branches’ together to hint [about] this. And we can also say about the matter from the angle of the simple understanding as well, that this is to fix in our souls the trait of compassion and to distance us from the trait of cruelty — which is a bad trait. And therefore even though God permitted us [to eat] species of animals for our sustenance, He [also] commanded us that we not kill it and its child on one day to fix the trait of compassion in our souls.

The laws of the commandment: That which they, may their memory be blessed, said (Chullin 82a) that there is no distinction between it and its child and its child and it (the order is not important). And that which they said (Chullin 83a) that at four periods during the year, one who sells a beast to his fellow must inform him, “I sold the mother for slaughter” — because at these four times, all purchasers presumably buy to slaughter [immediately]. And these are them: the eve of the last holiday of [Sukkot]; the eve of the first holiday of Pesach; the eve of [Shavuot]; and the eve of Rosh HaShanah. And according to the words of Rabbi Yose HaGalili, also on the eve of Yom Kippur in the Galilee. And behold, that which we learned that he needs to inform him — it is specifically the seller that has to inform [of] the thing. But the buyer need not ask, as it is a double doubt for him: lest it does not have a mother; and [even] if it does, perhaps [the seller] did not sell it for slaughter. And that which they said (Chullin 82a) [regarding] two people that bought a cow and its child — that the one who purchased first, slaughters first; but if the second preceded him and slaughtered against the law, the first is forbidden to slaughter. And the law of slaughtering a cow and two of her children, or her two children and her afterwards; and so [too,] it and her daughter and the daughter of her daughter. And it is permitted to slaughter the mother and the daughter of her daughter, as the Torah only forbade “it and its child.”

And that which they said that if one slaughters the mother and the daughter of her daughter, and then the daughter, he is only lashed forty [lashes]. And [that is] even though he transgresses two negative commandments on account of “it and its child” and on account of “its child and it” — nonetheless it is [still] one deed.

And that which they, may their memory be blessed, said (Chullin 78b) that the prohibition of “it and its child” is only practiced with females (mothers) — as they said in explanation of “its child,” the one who the child is attached to, which is the [mother]. And nevertheless, we conclude in Chullin 79a — with the good commentaries — that if the thing becomes clear to us that this is certainly its father, we [may] not slaughter it and its child on the same day; because we determine there that the law [follows] Rabbi Yehudah. And according to what is implied from his words, Rabbi Yehudah is in doubt if we concern ourselves with the seed of the father or not — [as] he says regarding the forbidden mixtures with mules [that] we do not mate a horse nor a donkey with it, but only its [own] species. And if he reasoned that we certainly do not concern ourselves with the seed of the father, he would not have said that. Rather, he would have had to say thus: “We only mate it [with] its species from the side of the mother.” But rather Rabbi Yehudah is certainly in doubt. And when he said [that] we do not concern ourselves with the seed of the father, his intention was to say that we do not concern ourselves with the seed of the father to be lenient about a thing; but to be stringent, we definitely concern ourselves with the seed of the father. And [likewise,] in any place that a stringency will result from saying that we are not concerned, then we say that we are not concerned for [the father]. As since it was a doubt for him, we go towards stringency in every case. And according to this, when we definitively know the [identity of the father] we should be concerned for him regarding “it and its child.” And the rest of its details are in the eighth chapter of Chullin. (See Tur, Yoreh Deah 16.)

The commandment is practiced in every place and at all times by males and females. And one who transgresses this and slaughtered “it and its child on one day” — or its child and it — is lashed.