19 "But for right now, copy down this song and teach the People of Israel to sing it by heart. They'll have it then as my witness against them. 20 When I bring them into the land that I promised to their ancestors, a land flowing with milk and honey, and they eat and become full and get fat and then begin fooling around with other gods and worshiping them, 21 and then things start falling apart, many terrible things happening, this song will be there with them as a witness to who they are and what went wrong. Their children won't forget this song; they'll be singing it. Don't think I don't know what they are already scheming to do, and they're not even in the land yet, this land I promised them."
22 So Moses wrote down this song that very day and taught it to the People of Israel.
Matthew Henry's Commentary on Deuteronomy 31:19-22
Commentary on Deuteronomy 31:14-22
(Read Deuteronomy 31:14-22)
Moses and Joshua attended the Divine Majesty at the door of the tabernacle. Moses is told again that he must shortly die; even those who are most ready and willing to die, need to be often reminded of its coming. The Lord tells Moses, that, after his death, the covenant he had taken so much pains to make between Israel and their God, would certainly be broken. Israel would forsake Him; then God would forsake Israel. Justly does he cast those off who so unjustly cast him off. Moses is directed to deliver them a song, which should remain a standing testimony for God, as faithful to them in giving them warning, and against them, as persons false to themselves in not taking the warning. The word of God is a discerner of the thoughts and intents of men's hearts, and meets them by reproofs and correction. Ministers who preach the word, know not the imaginations of men; but God, whose word it is, knows perfectly.