Psalms 29:7 - Albert Barnes' Notes on the Bible

Divideth the flames of fire - Margin, “cutteth out.” The Hebrew word - חצב châtsab - means properly “to cut, to hew, to hew out;” as, for example, stones. The allusion here is undoubtedly to lightning; and the image is either that it seems to be cut out, or cut into tongues and streaks - or, more probably, that the “clouds” seem to be cut or hewed so as to make openings or paths for the lightning. The eye is evidently fixed on the clouds, and on the sudden flash of lightning, as if the clouds had been “cleaved” or “opened” for the passage of it. The idea of the psalmist is that the “voice of the Lord,” or the thunder, seems to cleave or open the clouds for the flames of fire to play amidst the tempest. Of course this language, as well as that which has been already noticed Psalms 29:5, must be taken as denoting what “appears” to the eye, and not as a scientific statement of the reality in the case. The rolling thunder not only shakes the cedars, and makes the lofty trees on Lebanon and Sirion skip like a calf or a young unicorn, but it rends asunder or cleaves the clouds, and cuts out paths for the flames of fire.