Psalms 18:12

At the brightness that was before him— At his lightning his clouds swelled, and burst out into hailstones and coals of fire. Schultens, Chandler, &c. The meaning is, that at the brightness or lightning which proceeded from God, his clouds fermented, i.e. being rarefied by the heat, swelled and boiled over. Thus Hesiod represents the whole earth, the currents of the ocean, and the great sea, as fermenting and boiling, when Jupiter threw abroad his thunder and lightning. See Theog. ver. 695, 696. In the former part of this description, the clouds are represented as condensed, heavy, and louring, ready to burst out with all the fury of a tempest; and here, as beginning to disburthen and discharge themselves, by the eruption of the lightning in fire, flames, and hailstones, mixed: the abrupt manner in which the burning coals and hailstones are mentioned, points out the sudden and impetuous fall of them. The word גחלי gachalei, rendered coals, signifies living, burning coals. Where the lightning fell, it devoured all before it, and turned whatever it touched into burning embers. Chandler.