Deuteronomy 31:16; Deuteronomy 31:20

16 And the LORD said to Moses: “You are going to rest with your ancestors, and these people will soon prostitute themselves to the foreign gods of the land they are entering. They will forsake me and break the covenant I made with them.

20 When I have brought them into the land flowing with milk and honey, the land I promised on oath to their ancestors, and when they eat their fill and thrive, they will turn to other gods and worship them, rejecting me and breaking my covenant.