There were three sets of stones upon which the Torah was written: one was erected by Moses in the land of Moab, one by Joshua in Jordan, and one by Joshua in Gilgal (Sotah 35b).
"His firstling, majesty is his" (Deuteronomy 33:17). This refers to Joshua, who caused the sun and the moon to stand still. When the Holy One appeared to Joshua, He found him sitting with the Book of Deuteronomy in his hand. The Lord said to him: "Strengthen yourself, Joshua, persevere, Joshua..." Joshua took the Book, displayed it before the sun, and said, "Because I have not ceased from studying this Book, you must cease from moving at my request." Immediately, "the sun's movement ceased, and the moon stood still" (Joshua 10:13) (Bereishit Rabbah 6:9).
"He shall cause them to inherit the Land" (Deut. 3:28). This teaches that Joshua was not to depart this world until he had given Israel possession of the Land (Sifre Pinchas 136). He was the disciple of Judaism's greatest leader and lawgiver, Moshe Rabbenu, Moses our teacher. He gave definition to the Hebrew term meshores ("servant"), for serving Moses, no matter how small or simple the task, was never perceived by this future leader of our people as demeaning or servile. And so, as the Book of Deuteronomy closed, Joshua took up the reins of leadership, blessed by his patron Moses, and "full of the spirit of wisdom" (Deut.34:9).
It was, after all the sojourns and wilderness crises, all the attendant fears and anxieties, a comparatively quick and successful campaign to conquer the Promised Land. Or was it? The question is a natural one, and not only on account of the Israelites' difficulty throughout the Wilderness period. There were many adversaries in Canaan; further, the Book of Judges has led scholars to surmise that the original conquest of the Land, presented in the Book of Joshua, was neither as comprehensive or decisive as it is represented here.
What is represented here is a theology and a succession of leadership from one generation to the next. The demanding God of Deuteronomy is in evidence in conjunction with His might and power. Joshua is entrusted with the generalship of a new nation, and is advised by his Commander-in-Chief: "Only be strong and very courageous, being careful to do according to all the law which Moses my servant commanded you... for the Lord your God is with you wherever you go" (Josh.1:9). Judging the contents of Joshua's Book alone, the Lord's declaration is supported not only by Joshua's military successes but by the miracles and signs with which he is also empowered. Joshua, the son of Nun, the servant of Moses, the successor of Moses, the leader of the conquest of Canaan.