Why does it say "Gam Choshech Lo Yachshich Mimeka"?
Radak: The matter is repeated three or four times, to teach that it is so; there is no darkness to cover from Hashem. "Yachshich" is Po'el Yotzei, to darken something [from You, so You will not see it].
Malbim: Hashem does not see via a sensory eye, that He would need light to see.
Does night illuminate like day?
Radak: Yes, for Hashem. Malbim - the time of darkness does not impede him, and not a place where light does not break through.
What is the meaning of "ka'Chashechah ka'Orah"?
Rashi: Both of them are the same for You. Radak - the two prefixes "Kaf" equate the two matters, like "Chamocha k'Pharaoh" (Bereishis 44:18) and similar verses.
