Deuteronomy 31:4

4 And the LORD will do to them as He did to Sihon and Og, the kings of the Amorites, when He destroyed them along with their land.

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 he said to them, “I am now a hundred and twenty years old; I am no longer able to come and go, and the LORD has said to me, ‘You shall not cross the Jordan.’

3 The LORD your God Himself will cross over ahead of you. He will destroy these nations before you, and you will dispossess them. Joshua will cross ahead of you, as the LORD has said.

4 And the LORD will do to them as He did to Sihon and Og, the kings of the Amorites, when He destroyed them along with their land.

5 The LORD will deliver them over to you, and you must do to them exactly as I have commanded you.

6 Be strong and courageous; do not be afraid or terrified of them, for it is the LORD your God who goes with you; He will never leave you nor forsake you.”