Joshua is bidden to allot the whole of the promised land among the twelve tribes in faith that God would perfect in due time that expulsion of the Canaanites which Joshua himself could not carry further (see Joshua 11:23).
Related Commentaries of Joshua 13:1
Joshua 13:1
1 Now Joshua was old and stricken in years; and the LORD said unto him, Thou art old and stricken in years, and there remaineth yet very much land to be possessed.