John Calvin Commentary Deuteronomy 12:31

"Thou shalt not do so unto Jehovah thy God: for every abomination to Jehovah, which he hateth, have they done unto their gods; for even their sons and their daughters do they burn in the fire to their gods." — Deuteronomy 12:31 (ASV)

You shall not do so. From these words we may gather what it means not to make for oneself the gods of others: namely, to bid farewell to all human inventions and to pay attention to this one thing—what God commands.

For why does God desire to be worshipped by His elect people differently from how the nations were accustomed to serving their gods, if not because there ought to be a notable distinction, so that religion may not be confused? And surely, unless people adhere to God’s word, and so resolutely determine that nothing is permitted to them except what is taught there, they will not only be vacillating but will also indiscriminately receive whatever comes their way.

We must then hold fast to this: You shall not do so; and our minds must be restrained by this curb, lest any superstition which may defile the service of God should insinuate or establish itself. He adds that God not only repudiates these strange forms of worship but even abominates them. To emphasize this further, he cites one form of superstition in which its absurdity was particularly evident: for it is a foul barbarity that innocent children should be burned by their parents.