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.