Deuteronomy 31:3
The LORD thy God, he will go over before thee, and he will destroy these nations from before thee, and thou shalt possess them: and Joshua, he shall go over before thee, as the LORD hath said. The LORD thy God, he will go over before thee, and he will destroy these nations from before thee, and thou shalt possess them: and Joshua, he shall go over before thee, as the LORD hath said.
The verse stands in Moses' closing instruction in Deuteronomy 22 to 34, which is solemn, hopeful, cheering, and earnest and sets forth the grave responsibilities and fearful curses of transgression. It belongs to Moses' final discourse and charge as he lays down his work and hands it to another, commissioning Joshua as his successor in command. It was spoken together with the delivery of the law to the priests, as part of the final charge to the priests and to Joshua. Its setting is the close of Moses' life, with Joshua as his lieutenant and successor whose leadership begins as Israel prepares to cross the Jordan.
It promises that the Lord himself will cross over ahead of Israel, destroy the nations before them, and give them possession of their land, and that Joshua will cross over ahead of them as the Lord has said. It displays the second blessing of the promissory covenant to Abraham, the gift of the literal land of Canaan to his natural seed. That fulfillment proves the promise was the literal Canaan possessed under Joshua and not the New Earth.