From the middle of the river - i. e. as appears from Joshua 13:9, Joshua 13:16, "from the city that is in the midst of the river;" namely,, Ar Moab (see Deuteronomy 2:36).

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, Numbers 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, Deuteronomy 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 Joshua 12:5; and so Jarchi remarks.

On Sihon and his kingdom, see Numbers 21:24; Deuteronomy 2:36; Deuteronomy 3:16-17. "Aror on the Arnon:" the present ruins of Araayr, on the northern bank of the Mojeb (see Numbers 32:34). הנּחל ותוך, "and (from) the middle of the valley onwards:" i.e., according to the parallel passages in Joshua 13:9, Joshua 13:16, and Deuteronomy 2:36, from the town in the Arnon valley, the city of Moab mentioned in Numbers 22:36, viz., Ar or Areopolis (see at Numbers 21:15) in the neighbourhood of Aror, which is mentioned as the exclusive terminus a quo of the land taken by the Israelites along with the inclusive terminus Aror. "Half-Gilead," i.e., the mountainous district on the south side of the Jabbok (see at Deuteronomy 3:10), "to the river Jabbok," i.e., the upper Jabbok, the present Nahr Ammn (see at Numbers 21:24).

Sihon king of the Amorites, who dwelt in Heshbon, and ruled from Aroer, which is upon the bank of the river Arnon, and from the middle of the river, and from half Gilead, even unto the river Jabbok, which is the border of the children of Ammon;

12:2 Middle of the river - It is not unusual even among us, for a river to be divided between two lords, and for their territories or jurisdictions to meet in the middle of the river: and besides, here is a very particular reason for this expression, because the city Ar, which was no part of Sihon's dominions, but belonged to the Moabites, Deut 2:9,18, was in the middle of the river Arnon, Deut 2:36 3:16, and therefore the middle of the river is properly here mentioned, as the bound of Sihon's dominion on that side. Half Gilead - Heb. and the half Gilead, that is, half of the country of Gilead; this doth not denote the bound from which his dominion began, but the country, over which his dominion was, which began at Arnon, and took in half Gilead, and ended at Jabbok, beyond which was the other half of Gilead which belonged to Og.

12:1-6 Fresh mercies must not drown the remembrance of former mercies, nor must the glory of the present instruments of good to the church diminish the just honour of those who went before them, since God is the same who wrought by both. Moses gave to one part of Israel a very rich and fruitful country, but it was on the outside of Jordan. Joshua gave to all Israel the holy land, within Jordan. So the law has given to some few of God's spiritual Israel worldly blessings, earnests of good things to come; but our Lord Jesus, the true Joshua, provided for all the children of promise spiritual blessings, and the heavenly Canaan.