Psalms 104:2

Who coverest thyself with light as with a garment - Referring to the first work of creation Genesis 1:3, “And God said, Let there be light, and there was light.” He seemed to put on light as a garment; he himself appeared as if invested with light. It was the first “manifestation” of God. He seemed at once to have put on light as his robe.

Who stretchest out the heavens like a curtain - As an expanse spread over us. The word used here means a curtain or hanging, so called from its tremulous motion, from a word meaning to tremble. Thus it is applied to a curtain before a door; to a tent, etc. It is applied here to the heavens, as they seem to be “spread out” like the curtains of a tent, as if God had spread them out for a tent for himself to dwell in. See the notes at Isaiah 40:22.