Psalms 104:2

2. Who coverest thyself with light The text simply roads, “Who coverest with light,” there being nothing answering to “thyself” except the masculine form of the participle, while the object of the verb is left to be suggested by the connexion. Exley ( Commentary on Genesis) understands it of covering, or overspreading, the earth with “light,” being the first day’s work. Genesis 1:3-5. This gives a good sense, and certainly the psalmist already begins, in the second member of this verse, to speak of the acts of God in the six days’ work.

Stretchest out the heavens An allusion to the second day’s work, “Let there be a firmament,” etc.

Genesis 1:6-7. The action of this day’s work was upon the atmosphere, adapting it in a higher degree, as the pabulum of life, to plants and animals, and especially to the higher uses of man. The disordered state of the atmosphere prior to this was a prominent feature of the Hebrew cosmogony. In Job 38:9, the “cloud” and “thick darkness,” or the darkness of thick clouds, ( ערפל ,) is represented as “swaddling” the abyss. But the air now becomes pellucid, elastic, and animating.

Like a curtain The word means a hanging, or covering, of a flexible and tremulous substance, like a tent cloth, sometimes, the tent itself. Thus the sky, or expanse, seemed spread out like a tent covering. The present participial form of the verbs ( art covering, art stretching out, or spreading) teaches a present connexion of God with his universe, as if the acts of creation were still perpetuated in an all sustaining providence.