John Calvin on Leviticus 22:28-31

28. And whether it be a cow or ewe. Though cruelty was indeed condemned in this precept, still I make no doubt but that Moses speaks primarily of the sacrifices. I confess the word שחט, shachat, which he uses, is a general one; but since throughout the chapter he is professedly treating of the sacrifices, and in connection with these words adds the conclusion respecting the hallowing of His holy name, ver. 32, the context requires that we should consider it to be an inculcation of purity in God’s service. If any prefer to extend it further, I will not contest the point; and thus this sentence will be a supplement to the Sixth Commandment. I have, however, followed what appears most probable, and the reader of sound judgment will, I hope, agree with me. Meanwhile, I confess that all barbarity and cruelty was thus prohibited in the sacrifices, and in them the rule was laid down, that men should not be cruel in reference to their daily food. It is a sight by no means pleasant to gentle minds to see the dam killed together with her young; and, if it were a common custom, men would easily grow callous as to blood-shedding in general. God would therefore not have the exercises of religion disconnected from the duties of humanity; and the tendency of the precept is, that God’s altar should not be a Cyclopean slaughter-house.

Exodus 23

Exodus 23:19

19. ... Thou shalt not seethe a kid in his mother’s milk.

19. Non coques hoedum in lacte matris suae.