Psalms 18:8

There went up a smoke out of his nostrils, and fire out of his mouth devoured: coals were kindled by it.

There went up a smoke out of his nostrils - an expansion of Psalms 18:7, "He was wroth." The imagery is from Deuteronomy 32:22; Deuteronomy 29:20. The nostrils are in Hebrew conception the seat of anger.

Fire out of his mouth devoured - the fire and its accompanying smoke metaphorically express the heat of God's anger.

Coals were kindled by it or 'from it' - i:e., from His mouth. The "coals" in Psalms 18:12 are distinct from those here. Here they mean the wrath of Yahweh kindled: there they mean the lightnings which result from this wrath.