The Song of Moses was given to Moses and Joshua by God Himself to teach the leaders and the people of Israel. It predicted the turning away of the people…
Make a joyful noise unto the LORD, all ye lands. Serve the LORD with gladness: come before his presence with singing. Know ye that the LORD he is God: it is he that hath made us, and not we ourselves; we are his people, and the sheep of his pasture. ~ Psalm 100:1-3