His light, i.e. the lightning; of which the whole context speaks, which is fitly called God's light, as it is called God's lightning, Psalms 144:6, because God only can light it. Upon it, i.e. upon the cloud, which is in a manner the candlestick in which God sets up this light. Covereth the bottom of the sea; the lightning spreads far and wide over all the parts of the sea, and pierceth deep, reaching even to the bottom of it, and spreading itself upon it, and so covering it like a gay and glorious garment, suddenly cast over and covering the body of a man or woman; or as God is said to cover himself with light as with a garment, Psalms 104:2.
Related Commentaries of Job 36:30
Job 36:30
30 Behold, he spreadeth his light upon it, and covereth the bottomg of the sea.