The Lord shall go forth - This and the following verses give the reasons why they should praise Yahweh. He would go forth in his might to overcome and subdue his foes, and to deliver his people. In his conquests, and in the establishment of his kingdom, all people would have occasion to rejoice and be glad.
As a mighty man - As a hero, as a warrior. Yahweh is often in the Scriptures represented as a hero, or a man of war:
Yahweh is a man of war:
Yahweh is his name. - Exodus 15:3.
Who is this King of glory?
Yahweh, strong and mighty;
Yahweh mighty in battle. - Psalms 24:8.
Compare Psalms 45:3; Isaiah 27:1; Isaiah 30:30,
He shall stir up jealousy - He shall rouse his vengeance, or his indignation. The word קנאה qin'âh means vengeance, or indignation, as well as jealousy. The image here is that of a warrior who rushes on impetuously to take vengeance on his foes.
He shall cry - He shall give a shout, or a loud clamor. Warriors usually entered a battle with a loud shout, designed to stimulate their own courage, and to intimidate their foes. All this language is taken from such an entrance on an engagement, and denotes the fixed determination of God to overthrow all his enemies.