איוב כג:יז פירוש: רש״י

Because I was not cut off from before the darkness Because of this I am startled; because I was not completely cut off and laid permanently in the grave before this darkness that has come upon me, and because He did not cover this thick darkness from before me until my death.

and [because He did not] cover the thick darkness from before me This refers back to “because not” at the beginning of the verse.