Translation:

38. At length when (such a one) comes to Us he says (to his evil companion): "Would that between me and thee were the distance of East and West!" Ah! Evil is the companion (indeed)!

Notes (Tafseer)

4640. If ever the presence of Allah is felt, or at the time of Judgment, a glimmering of truth comes to the deceived soul, and it cries to its evil companion in its agony, "Would that I had never come across thee! Would that we were separated poles apart!" But it cannot shake off evil. By deliberate choice it had put itself in its snare.

4641. Distance of East and West: literally, 'distance of the two Easts'. Most Commentators understand in this sense, but some construe the phrase as meaning the distance of the extreme points of the rising of the sun, between the summer solstice and the winter solstice. Cf. n. 4034 to xxxvii. 5. A good equivalent idiom in English would be "poles apart", for they could never meet.