Here "arm" represents the power of God. It is implied that Yahweh will show his power by destroying his people's enemies. Alternate translation: "show that he is powerful by destroying your enemies" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-explicit]])
Yahweh's anger is spoken of as if it were a storm or a fire. Alternate translation: "in anger that is like a storm and flames of fire" or "in great anger" (See: [[rc://en/ta/man/jit/figs-metaphor]])