en_tn/isa/42/13.md

Yahweh will go out as a warrior; as a man of war

Yahweh is compared with a warrior who is ready to defeat his people's enemies. (See: rc://en/ta/man/jit/figs-simile and rc://en/ta/man/jit/figs-parallelism)

he will stir up his zeal

Here "zeal" refers to the passion that a warrior experiences when he is about to fight a battle. Yahweh stimulating his zeal is spoken of as if he stirred it up like the wind stirs up waves of water. (See: rc://en/ta/man/jit/figs-metaphor)