Deuteronomy 12:32

“What thing soever I command you, observe to do it, etc.] In the manner it is commanded and directed to; the laws of God, both as to matter and manner, were to be obeyed just as they were delivered: thou shall not add thereto, nor diminish from it; neither add any customs and rites of the Heathens to them, nor neglect anything enjoined on them, (see <203006> Proverbs 30:6 <662218>Revelation 22:18,19).”

“thou shalt not: Deu 4:2, Deu 13:18; Jos 1:7; Pro 30:6; Mat 28:20; Rev 22:18, Rev 22:19 Next: Deuteronomy Chapter 13”

“The admonition to observe the whole law, without adding to it or taking from it (cf. Deu 4:2), is regarded by many commentators as the conclusion of the previous chapter. But it is more correct to understand it as an intermediate link, closing what goes before, and introductory to what follows. Strictly speaking, the warning against inclining to the idolatry of the Canaanites ( Deu 12:29-31) forms a transition from the enforcement of the true mode of worshipping Jehovah to the laws relating to tempters to idolatry and worshippers of idols (ch. 13). The Israelites were to cut off not only the tempters to idolatry, but those who had been led astray to idolatry also. Three different cases are…”