God is represented as wrapping Himself in a robe of light. Robert Grant’s hymn “O Worship the King” has in its second stanza the phrase, “whose robe is the light, whose canopy space.” Light both conceals and reveals (see John 1:4-9; 1 John 1:5).
Verses 2-4 may be compared with the work of the first two days of creation, when light and the firmament were created to replace darkness and chaos (see Gen. 1:3-8).