31:1-8 Moses assures Israel of the constant presence of God with them. This is applied by the apostle to all God's spiritual Israel, to encourage their faith and hope; unto us is this gospel preached, as well as unto them; he will never fail thee, nor forsake thee, Heb 13:5. Moses commends Joshua to them for a leader; one whose wisdom, and courage, and affection they had long known; one whom God had appointed to be their leader; and therefore would own and bless. Joshua is well pleased to be admonished by Moses to be strong and of good courage. Those shall speed well, who have God with them; therefore they ought to be of good courage. Through God let us do valiantly, for through him we shall do victoriously; if we resist the devil, he will flee from us.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,

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.