Deuteronomy 4:2

“Ye shall not add to the word which I command you, nether shall you diminish ought from it, etc.] Neither make new laws of their own, and join them to the law of God, and set them upon a level with it, or prefer them before it; as the Scribes and Pharisees did in Christ’s time, who by their traditions made the word of God of none effect, as do the Papists also by their unwritten traditions; nor abrogate nor detract from the law of God, nor make void any part of it: or else the sense is, neither do that which is forbidden, nor neglect that which is commanded; neither be guilty of sins of omission nor commission, nor in any way break the law of God, and teach men so to do by word or by example;…”

“Ye shall not add unto the word which I command you--by the introduction of any heathen superstition or forms of worship different from those which I have appointed (Deu 12:32; Num 15:39; Mat 15:9). neither shall ye diminish aught from it--by the neglect or omission of any of the observances, however trivial or irksome, which I have prescribed. The character and provisions of the ancient dispensation were adapted with divine wisdom to the instruction of that infant state of the church. But it was only a temporary economy; and although God here authorizes Moses to command that all its institutions should be honored with unfailing observance, this did not prevent Him from commissioning other…”

“Deu 12:32; Jos 1:7; Pro 30:6; Ecc 12:13; Mat 5:18, Mat 5:43, Mat 15:2-9; Mar 7:1-13; Gal 3:15; Rev 22:18, Rev 22:19 Deuteronomy 4:3”