Albert Barnes Commentary 1 Chronicles 7:17

"And the sons of Ulam: Bedan. These were the sons of Gilead the son of Machir, the son of Manasseh." — 1 Chronicles 7:17 (ASV)

These were the sons of Gilead—that is, these descendants of Machir were considered part of the family of Gilead. The name “Gilead” prevailed above all others in the line of Manasseh, with the term “Gileadite” almost taking the place of “Manassite.”