Deuteronomy 31:19-22

19“So write down the words of this song, and teach it to the people of Israel. Help them learn it, so it may serve as a witness for me against them.

20For I will bring them into the land I swore to give their ancestors—a land flowing with milk and honey. There they will become prosperous, eat all the food they want, and become fat. But they will begin to worship other gods; they will despise me and break my covenant.

21And when great disasters come down on them, this song will stand as evidence against them, for it will never be forgotten by their descendants. I know the intentions of these people, even now before they have entered the land I swore to give them.”

22So that very day Moses wrote down the words of the song and taught it to the Israelites.