Psalms 139:11

Surely the darkness shall cover me - Should I suppose that this would serve to screen me, immediately this darkness is turned into light.

If I say, Surely the darkness shall cover me - If I seek to find refuge in the darkness of the night so that God would not see me. The word rendered "cover" - שׁוף shûph - means properly to snap, to gape after; then, to lie in wait for; and then, to attack, or fall upon anyone, unexpectedly. It is rendered "bruise" (twice) in Genesis 3:15, "He shall "bruise" thy head, and thou shalt "bruise" his heel;" "breaketh" in Job 9:17, "He "breaketh" me with a tempest;" and in this place "cover." It does not occur elsewhere. Here it means to fall upon; to overpower; to cover. The idea is, If it should come suddenly upon me; if I should be involved in sudden darkness - "as if" the darkness should come and attempt to "snatch" me away from God. All this would be in vain, for it would be, so far as God is concerned, bright day around me.

Even the night shall be light about me - In respect to me. It shall be as if I stood in the full blaze of light. God can see me still; he can mark my goings; he can perceive all that I do as plainly then as at mid-day. This "is" so: and what a thought this is for a wicked man who seeks to escape detection in his crimes by perpetrating them in the night! What a thought for a good man, that in the darkest night of sorrow, when there seems to be nothing but deep midnight, when there appears to be not a ray of light in his dwelling, or on his path that all to the eye of God is as clear as noon-day! For in that night of sorrow God sees him as plainly as in the brightest days of prosperity and joy.