Deuteronomy 31:4

4 The LORD will do to those nations what he did to King Sihon and King Og of the Amorites and to their lands when he destroyed them.

Deuteronomy 31:4 Meaning and Commentary

Deuteronomy 31:4

And the Lord shall do unto them as he did unto Sihon, and to
Og, kings of the Amorites
Deliver them up into their hands; see the history of this in ( Numbers 21:10-35 ) ;

and unto the land of them whom he destroyed;
put them into the possession of the land of Canaan, as they were now in possession of the land of those two kings he destroyed by them. This instance is given to encourage their faith, assuring them that what had been done to them would be done to the Canaanitish kings, and their subjects, and their lands.

Deuteronomy 31:4 In-Context

2 "I'm 120 years old now, and I'm not able to lead you anymore. Besides, the LORD has told me that I cannot cross the Jordan River.

3 The LORD your God is the one who will cross the river ahead of you. He will destroy those nations as you arrive, and you will take possession of their land. Joshua will also cross the river ahead of you, as the LORD told you.

4 The LORD will do to those nations what he did to King Sihon and King Og of the Amorites and to their lands when he destroyed them.

5 The LORD will hand them over to you, and you must do to them everything that I commanded you.

6 Be strong and courageous. Don't tremble! Don't be afraid of them! The LORD your God is the one who is going with you. He won't abandon you or leave you."