Deuteronomy 31:20-21

201For when I bring them into the land flowing with milk and honey, which I swore to their fathers, and they eat and are satisfied and 2become 3prosperous, then they will turn to other gods and serve them, and spurn Me and break My covenant.

21Then it will come about, 4when many evils and troubles find them, that this song will testify before them as a witness (for it shall not be forgotten from the mouth of their 5descendants); for 6I know their inclination which they are 7developing today, before I bring them into the land which I swore.”