The Lord is the only God. There is no one beside him.
The Lord made himself known to Israel. They alone heard his voice through the fire. And The Lord handed over to them nations that are mightier and greater than they were.
Moses warns Israel to not forget this and to not start making worshipping carved images in the likeness of created things, and nature itself, like the sun and the stars. He tells them that if they do they will not live long in the promise land which they were about to go to. They will be driven out and scattered among the nations, where they will worship false gods. But Moses tells them that they will cry out to the Lord and He will be merciful to them.