This verse gives the grounds for praising Yahweh. People must praise him because he fights his enemies like a mighty warrior. The prophet uses military imagery to describe the LORD, which is common in the Old Testament (see, for example, 10.20-23; Exo 15.3; Jdg 5.4; Psa 24.8).
The LORD goes forth like a mighty man: In this line Yahweh is compared to a mighty soldier who goes to fight an enemy. The Hebrew verb rendered goes forth can mean simply “to go out” or “to leave.” Here it has the sense of going out to battle, so Good News Translation says “goes out to fight.” The Hebrew term translated mighty man refers here to a “warrior” (Good News Translation), who has great physical strength (see the comments on 3.2).
Like a man of war he stirs up his fury is parallel to the previous line. This time Yahweh is compared to a soldier who is passionate about fighting. For the Hebrew phrase rendered man of war, see the comments on 3.2, where it is translated “soldier.” It has the same sense as mighty man here, so Good News Translation combines them into “warrior.” Revised English Bible uses “warrior” in the previous line and “soldier” here, which may be a helpful model for other languages. The Hebrew verb rendered stirs up is the same one that occurs in 41.2, 25. The Hebrew word for fury is the same one translated “zeal” in 9.7 (see the comments there). Here it refers to a strong passion for fighting. In English he stirs up his fury means he becomes very angry. New Jewish Publication Society’s Tanakh is similar with “He whips up His rage.” However, these renderings do not express the Hebrew here accurately. Good News Translation expresses it better with “he is ready and eager for battle.” Another possible model is “he fights with passion.”
He cries out, he shouts aloud: These two synonymous clauses describe the LORD preparing for battle by letting out a battle cry. New American Bible combines them by saying “He shouts out his battle cry,” which may be helpful model for other languages. Another possible model is “He lets out a war cry.”
He shows himself mighty against his foes: The Hebrew verb rendered shows himself mighty comes from the same root as the noun translated mighty man in the first line. Yahweh attacks his enemies like a warrior. For this line New International Version has “and will triumph over his enemies,” but this seems to say more than the Hebrew text does. A better rendering is “he shows no fear when he attacks his enemies.”
New International Version uses the future tense throughout this verse, saying “The LORD will march out like a mighty man, like a warrior he will stir up his zeal; with a shout he will raise the battle cry and will triumph over his enemies” (similarly Revised English Bible). The Hebrew syntax here allows for present or future tense. Since this verse gives the reasons for praising God, the present tense fits better. Normally we praise God for things he has done or is doing.
For the translation of this verse consider the following examples:
• Yahweh goes into battle like a warrior,
like a soldier he fights with passion.
He utters a battle cry, he shouts a war cry;
he attacks his enemies without fear.
• The LORD goes out to battle like a warrior,
fighting with great passion like a soldier.
He lets out a war cry, a battle shout;
he shows he is fearless as he attacks his enemies.
Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .