The "in (fi)" infers that in their view everything has ceased to exist and that nothing remains but the darkness, which seems to be non-existence and encases them like the grave.

The plural of "darkness(es) (zulumâtin)" indicates that the blackness of the night and tenebrous clouds have given rise to the darkness of despair and fear in their spirits, and that where they are found is filled with the darkness of desolation and despondency. For them time too is filled with the darkness of silence and motionlessness. It suggests that they are entirely swathed in multifarious darknesses. The use of the indefinite signifies that the darkness is unknown to them, their never before having experienced it, and this increases its impact on them.

As for "they cannot see (lâ yubsirûn)," it states clearly the worst calamities. For the person who cannot see suffers more tribulations, and because he lacks sight he experiences [to a greater degree] the slightest misfortunes. The imperfect tense is used to depict their condition [vividly] in the eye of the imagination so the listener [actually] sees their consternation and his conscience is affected. The verb is without object to generalize [the meaning]; they cannot see anything that would be of use to them and might protect them, and they cannot see the dangers that they might avoid them; and they cannot see their companions to avail themselves of their intimacy. It is as though each is on his own and alone.

Next consider the phrases "Deaf, dumb, blind - and they cannot turn back (summun bukmun 'umyun fa-hum lâ yarji'ûn)" and listen to how they confide in one another. For these four [phrases] are a definition shared (hadd mushtarak) by both the parable or comparison (mumaththil) and the thing portrayed (mumaththal). They are intermediate between them and are turned to both. They tell of both sides' conditions, and are a mirror to both showing you their characters. They result from both and tell you their stories.

The aspect looking to the comparison: know that a person who is struck by such a calamity clings onto the hope of being saved by listening closely for the voice of someone who might save him. But the night is so silent and soundless it deafens him. Still he hopes to make someone hear, but the deafness of the night makes him dumb. Then he hopes to be guided by the sight of a fire or light, but the unseeing night makes him blind. Then [he hopes] to return to the start [of his journey] but the door is blocked up against him like one who falls into a bog and the more he struggles the more he sinks into it.