We know nothing about this Gilead. Other suppositions are less likely, such as: this is a reference to the familiar Gilead, the grandson of Manasseh, son of Joseph, after whom this region is named (Numbers 26:29–30). Then, Gilead would be the “ancestor” of Jephthah, and “son” would mean “descendant” here. Only, the given name “Gilead” may suggest that Jephthah’s father was a chief, that he was proud to be a Gileadite, and that he was the scion of the family tree. There could be a ring of patriotism in the name.
1 Now Jephthah the Gileadite was a mighty warrior, but he was the son of a prostitute. Gilead was the father of Jephthah.