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.
Matthew Henry: 'God gave him an excellent spirit, and he improved it bravely, Judges 11:29. When it appeared by the people's unanimous choice of him for their leader that he had so clear a call to engage, and by the obstinate deafness of the king of Ammon to the proposals of accommodation that he had so just a cause to engage in, then the Spirit of the Lord came upon him, and very much advanced his natural faculties, enduing him with power from on high, and making him more bold and more wise than ever he had been, and more fired with a holy zeal against the enemies of his people. Hereby God confirmed him in his office, and assure…