John Gill Commentary Psalms 18:14

"And he sent out his arrows, and scattered them; Yea, lightnings manifold, and discomfited them." — Psalms 18:14 (ASV)

Yea, he sent out his arrows By which thunderbolts, cracks of thunder, and flashes of lightning, seem to be meant; see (Psalms 77:17Psalms 77:18) (144:6); comparable to arrows shot, and sent out of a bow; and may denote, either the doctrines of the Gospel, which were sharp in the hearts of Christ's enemies, and are either the means of subduing them to him, or of destroying them, being the savour of death unto death; or however, like arrows, give great pain and uneasiness where they stick, and grievously distress and torment; as does the fire which comes out of the mouth of the two witnesses, (Revelation 11:5Revelation 11:10). The Targum is, ``he sent his word as arrows;'' or else the judgments of God are meant, as famine, pestilence, and the sword, which God sent unto, and spent upon the Jewish nation, (Deuteronomy 32:23);

and scattered them ; among the nations of the world, where they have been dispersed ever since;

and he shot out lightnings ; or "many lightnings", so the Targum:

and discomfited them ; troubled, terrified, and distressed them.