Deuteronomy 31:20-21

20For I shall bring them into the land which I swore unto their fathers, which floweth with milk and honey; and they will eat and fill themselves, and wax fat, and will turn unto other 1gods, and serve them, and despise me, and break my covenant.

21And it shall come to pass, when many evils and troubles have befallen them, that this song shall testify against them as a witness; for it shall not be forgotten out of the mouths of their seed; for I know their imagination which they are forming already this day, before I bring them into the land which I have sworn [unto them].