The word "ignite" means start a fire. Here Yahweh's anger is compared to that of a fire. Alternate translation: "the anger of Yahweh started to burn like a fire" (See: [[rc://en/ta/man/translate/figs-metaphor]])
In the law of Moses, God prohibited the kings of Israel from taking a census of fighting men. The full meaning of this statement can be made explicit. (See: [[rc://en/ta/man/translate/figs-explicit]])