Matthew Poole and continuators on Exodus 23:19

19 The first of the first-fruits of thy land, thou shalt bring into the house of the LORD thy God. Thou shalt not seethe a kid in his mothers milk .

This seems to be a general rule extending to all the fruits which the earth first produced in every kind of which the very first are here enjoyned to be offered unto God, before they should presume to eat any of them. It may seem to be repeated here where the year of rest is mentioned, to teach them the first-fruits were to be given to God of all that the earth produced, not onely by their labour and seed, as might be thought from ver. 16. but also of its own accord, as is here implyed.

He names one kind, under which he understands a lamb or a calf, &c. according to the use of Scripture-stile. This law many understand literally, and that it is forbidden to them, because the Idolaters had such a custome; whereof yet there seems to be no sufficient proof: nor, if there were, doth it seem to be a rite of that importance or probability to entice the Israelites to imitate it, that there needed a particular law against this more than against an hundred such ridiculous usages which were among the heathen, and are not taken notice of in the book of Gods laws. The words may be rendred thus, Thou shalt not seethe or rost (for the word bashal signifies to rost as well as to boyl, as it is evident from Deut. 16. 7. a kid being or whilest it is (which is to be understood, there being nothing more common than an Ellipsis of the verb substantive) in his mothers milk: which it may be said to be, either 1. whilest it sucks its mothers milk, and so it may admit of a twofold interpretation, 1. that this is to be understood of the Passeover, of which most conceive he had now spoken, v. 18. in which they used either a lamb or a kid, Exod. 12. 5. and then the word bashal must be rendred rost, 2. that this speaks not of sacrifice to God, wherein sucking creatures were allowed, Exod. 22. 30. Levit. 22. 27. 1 Sam. 7. 9. but of mans use, and so God ordained this partly because this was unwholesome food, and principally to restrain cruelty, even towards brute-creatures, and luxury in the use of them. Or rather 2. whilest it is very tender and young, rather of a milky than of a fleshy substance, like that young kid of which Iuvenal thus speaks, Qui plus lactis habit quàm sanguinis, i. e. which hath more milk than blood in it. And it may be said to be in its mothers milk, by an usual Hypallage, when its mothers milk is in it, i. e. whilest the milk it sucks as it were remains in it undigested and unconverted into flesh, even as a man is oft said to be in the spirit, when indeed the spirit is in him. And what is here indefinitely prohibited, is elsewhere particularly explained and the time defined, to wit, that it be not offered to God before it was eight days old. And this interpretation may receive light and strength from hence, that the law of the first-fruits, which both here and Exod. 34. 26. goes immediately before this law, doth in Exod. 22. 30. immediately go before that law of not offering them before the eighth day, which implies, that both of them speak concerning the same thing, to wit, the first-fruits or first-born of the cattel, which were not to be offered to God, while they were in their mothers milk, saith this place, or till they were 8 days old, saith that place. And consequently, if they might not be offered to God, they might not be used by men for food.

Marginal references: Deut. 14. 21.