Albert Barnes Commentary Job 17:13

"If I look for Sheol as my house; If I have spread my couch in the darkness;" — Job 17:13 (ASV)

If I wait — Or more accurately, “truly I expect that the grave will be my home.” The word rendered “if” (אם 'im) is often used in such a sense. The meaning is, “I look certainly to the grave as my home. I have made up my mind to it, and have no other expectation.”

The grave — Hebrew שׁאול she'ol. It may mean here either the grave, or the region of departed spirits, to which he expected soon to descend.

Mine house — My home; my permanent abode.

I have made my bed — I am certain of making my bed there. I shall soon lie down there.

In the darkness — In the grave, or in the dark world to which it leads; see the notes at Job 10:21-22.