"The Israelites crossed the river Arnon and advanced upon the foe. An engagement took place, in which the armies of Israel were victorious; and, following up the advantage gained, they were soon in possession of the country of the Amorites. It was the Captain of the Lord's host who vanquished the enemies of His people; and He would have done the same thirty-eight years before had Israel trusted in Him . PP 435.1"
"And he said, Nay; but as captain of the host of the Lord am I now come. And Joshua fell on his face to the earth, and did worship, and said unto him, What saith my lord unto his servant?"
Both passages refer to the 'Captain of the Lord's host' being instrumental in Israel's victories. The EGW passage directly attributes the victory to this divine figure, echoing the concept presented in Joshua 5:14.
Filled with hope and courage, the army of Israel eagerly pressed forward, and, still journeying northward, they soon reached a country that might well test their courage and their faith in God. Before them lay the powerful and populous kingdom of Bashan, crowded with great stone cities that to this day excite the wonder of the world—“threescore cities ... with high walls, gates, and bars; besides unwalled towns a great many.” Deuteronomy 3:1-11 . The houses were constructed of huge black stones, of such stupendous size as to make the buildings absolutely impregnable to any force that in those times could have been brought against them. It was a country filled with wild caverns, lofty precipices, yawning gulfs, and rocky strongholds. The inhabitants of this land, descendants from a giant race, were themselves of marvelous size and strength, and so distinguished for violence and cruelty as to be the terror of all surrounding nations; while Og, the king of the country, was remarkable for …
"Then we turned, and went up the way to Bashan: and Og the king of Bashan came out against us, he and all his people, to battle at Edrei. And the Lord said unto me, Fear him not: for I will deliver him, and all his people, and his land, into thy hand; and thou shalt do unto him as thou didst unto Sihon king of the Amorites, which dwelt at Heshbon. So the Lord our God delivered into our hands Og also, the king of Bashan, and all his people: and we smote him until none was left to him remaining. And we took all his cities at that time, there was not a city which we took not from them, threescore cities, all the region of Argob, the kingdom of Og in Bashan. All these cities were fenced with high walls, gates, and bars; beside unwalled towns a great many. And we utterly destroyed them, as we did unto Sihon king of Heshbon, utterly destroying the men, women, and children, of every city. But all the cattle, and the spoil of the cities, we took for a prey to ourselves. And we took at that time out of the hand of the two kings of the Amorites the land that was on this side Jordan, from the river of Arnon unto mount Hermon; (Which Hermon the Sidonians call Sirion; and the Amorites call it Shenir;) All the cities of the plain, and all Gilead, and all Bashan, unto Salchah and Edrei, cities of the kingdom of Og in Bashan. For only Og king of Bashan remained of the remnant of giants; behold, his bedstead was a bedstead of iron; is it not in Rabbath of the children of Ammon? nine cubits was the length thereof, and four cubits the breadth of it, after the cubit of a man."
Ellen White directly references Deuteronomy 3:1-11 in this passage.