Verse 29:[1] Then (Judg. 3:10) the Spirit of the LORD came upon Jephthah (Jepthah seems to have been Judge only of North-east Israel), and he passed over Gilead, and Manasseh, and passed over Mizpeh of Gilead, and from Mizpeh of Gilead he passed over unto the children of Ammon.
[The spirit of the Lord came upon Jephthah] A spirit of courage (the Chaldean in Vatablus). See what things are on Judges 3:10 (Menochius, Malvenda). Only the Gileadites had chosen Jephthah for themselves as Leader: But here God shows that He had determined him as Leader for all Israel (Martyr).
The Spirit of the Lord came upon Jephthah; endued him with a more than ordinary courage and resolution. Manasseh, that is, Bashan, which the half tribe of Manasseh, beyond Jordan, inhabited, Joshua 20:8; 21:6.
[And Mizpeh of Gilead] That is, Mizpeh, which is in the extreme borders of Gilead toward Libanus and Hermon; for the Ammonites, the neighboring enemies, were especially and most nearly threatening these (Lapide). This was a distinct city from Mizpeh of Judah[2] (Martyr).
Mizpeh of Gilead; so called, to distinguish it from other cities of that name. Having gathered what forces he suddenly could, he came hither to the borders of the Ammonites.
[1] Hebrew: וַתְּהִ֤י עַל־יִפְתָּח֙ ר֣וּחַ יְהוָ֔ה וַיַּעֲבֹ֥ר אֶת־הַגִּלְעָ֖ד וְאֶת־מְנַשֶּׁ֑ה וַֽיַּעֲבֹר֙ אֶת־מִצְפֵּ֣ה גִלְעָ֔ד וּמִמִּצְפֵּ֣ה גִלְעָ֔ד עָבַ֖ר בְּנֵ֥י עַמּֽוֹן׃
[2] See Joshua 15:38.