John Gill Commentary Deuteronomy 31:3

"Jehovah thy God, he will go over before thee; he will destroy these nations from before thee, and thou shalt dispossess them: [and] Joshua, he shall go over before thee, as Jehovah hath spoken." — Deuteronomy 31:3 (ASV)

The Lord your God, he will go over before you This he said to encourage the people of Israel; that though he should die, and not go over with them, their ever living and true God, the great Jehovah, the Lord of hosts, he would go before them, and fight their battles for them; so that they had nothing to fear from their enemies:

[and] he will destroy those nations from before you ; the seven nations which then inhabited the land:

and you shall possess them ; their countries, cities, and houses, fields, and vineyards:

[and] Joshua, he shall go over before you ; as their general to fight for them, subdue their enemies, and put them into the possession of the land, and divide it to them:

as the Lord has said ; (Deuteronomy 3:28) .