Joshua, or whoever else is the historian before he comes to sum up the new conquests Israel had made, in these verses receives their former conquests in Moses's time, under whom they became masters of the great and potent kingdoms of Sihon and Og. Note, Fresh mercies must not drown the remembrance of former mercies, nor must the glory of the present instruments of good to the church be suffered to eclipse and diminish the just honour of those who have gone before them, and who were the blessings and ornaments of their day. Joshua's services and achievements are confessedly great, but let not those under Moses be overlooked and forgotten, since God was the same who wrought both, and both put together proclaim him the Alpha and Omega of Israel's great salvation. Here is, 1. A description of this conquered country, the measure and bounds of it in general (Jos 12:1): From the river Arnon in the south, to Mount Hermon in the north. In particular, here is a description of the kingdom of Sihon (Jos 12:2, Jos 12:3), and that of Og, Jos 12:4, Jos 12:5. Moses had described this country very particularly (Deu 2:36; Deu 3:4, etc.), and this description here agrees with his. King Og is said to dwell at Ashtaroth and Edrei (Jos 12:4), probably because they were both his royal cities; he had palaces in both, and resided sometimes in one and sometimes in the other; one perhaps was his summer seat and the other his winter seat. But Israel took both from him, and made one grave to serve him that could not be content with one palace. 2. The distribution of this country. Moses assigned it to the two tribes and a half, at their request, and divided it among them (Jos 12:6), of which we had the story at large, Num. 32. The dividing of it when it was conquered by Moses is here mentioned as an example to Joshua what he must do now that he had conquered the country on this side Jordan. Moses, in his time, gave to one part of Israel a very rich and fruitful country, but it was on the outside of Jordan; but Joshua gave to all Israel the holy land, the mountain of God's sanctuary, within Jordan: so the law conferred upon some few of God's spiritual Israel external temporal blessings, which were earnests of good things to come; but our Lord Jesus, the true Joshua, has provided for all the children of promise spiritual blessings - the privileges of the sanctuary, and the heavenly Canaan. The triumphs and grants of the law were glorious, but those of the gospel far exceed in glory.

From Aroer - Aroer was situated on the western side of the river Arnon, in the middle of the valley through which this river takes its course. The kingdom of Sihon extended from the river Arnon and the city of Aroer on the south to the river Jabbok on the north.

And from half Gilead - The mountains of Gilead extended from north to south from Mount Hermon towards the source of the river Arnon, which was about the midst of the extent of the kingdom of Sihon: thus Sihon is said to have possessed the half of Gilead, that is, the half of the mountains and of the country which bore the name of Gilead on the east of his territories.

River Jabbok - This river has its source in the mountains of Gilead; and, running from east to west, falls into Jordan. It bounds the territories of Sihon on the north, and those of the Ammonites on the south.

Sihon king of the Amorites, who dwelt in Heshbon,.... Which he took from the Moabites, and made his capital city, Num 21:26,

and ruled from Aroer, which is upon the bank of the river of Arnon; a city of Moab, which never fell into the hands of Sihon, and therefore he is said to rule from it but not over it:

and from the middle of the river; that is, the river Arnon, which being the boundary of the Moabites and Amorites, the king of the Amorites might be said to rule from the middle of it:

and from half Gilead even unto the river Jabbok, which is the border of the children of Ammon; so it is said to be, Deu 3:16; it should be rendered, not "from half Gilead", but "and half Gilead", as it is in the Hebrew text, and so in the Targum; for half Gilead belonged to the kingdom of Sihon, as the other half did to the kingdom of Og, as in Jos 12:5; and so Jarchi remarks.