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.