Deuteronomy 3:15,16

Gilead That is, the half part of Gilead. To Machir

That is, unto the children of Machir, son of Manasseh, for Machir was now dead. Half the valley Or rather, to the middle of the river: for the word rendered half, signifies commonly middle, and the same Hebrew word means both a valley and a brook, or river. And this sense is agreeable to the truth, that their land extended from Gilead unto Arnon, and, to speak exactly, to the middle of that river; for as that river was the border between them and others, so one half of it belonged to them, as the other half did to others; see Joshua 12:2, where the same thing is expressed in the same words, in the Hebrew, though our translators render them there, from the middle of the river, and here, half of the valley.