Deuteronomy 31:19-22

19Therefore write down this song for yourselves and teach it to the Israelites; have them sing it, so that this song may be a witness for me against the Israelites.

20When I bring them into the land I swore to give their ancestors, a land flowing with milk and honey, they will eat their fill and prosper. They will turn to other gods and worship them, despising me and breaking my covenant.

21And when many troubles and afflictions come to them, this song will testify against them, because their descendants will not have forgotten it. For I know what they are prone to do, even before I bring them into the land I swore to give them.”

22So Moses wrote down this song on that day and taught it to the Israelites.