Who was Machir?
(1) Machir was the eldest son of Manasseh (Gen 50:23). In Nu 26:29 it is recorded that Machir begat Gilead, but another narrative informs us that the children of Machir "went to Gilead, and took it, and dispossessed the Amorites that were therein. And Moses gave Gilead unto Machir the son of Manasseh; and he dwelt therein" (Nu 32:39,40; Josh 17:1,3; compare also 1 Ch 2:21,25; 7:14-17; Dt 3:15; Josh 13:31). In the song of Deborah, Machir is used as equivalent to Manasseh (Jdg 5:14).
(2) Son of Ammiel, dwelling in Lo-debar (2 Sam 9:4,5), a wealthy landowner who protected Mephibosheth (Meribbaal), son of Jonathan, until assured of the friendly intentions of David (compare Ant, VII, ix, 8). Afterward, during the rebellion of Absalom, Machir with others came to David's assistance at Mahanaim, bringing supplies for the king and his men (2 Sam 17:27 ff).
IBSE, "Isaac" (in the public domain) with minor edits.