Charles Ellicott Commentary Psalms 139:8

"If I ascend up into heaven, thou art there: If I make my bed in Sheol, behold, thou art there." — Psalms 139:8 (ASV)

If I make my bed in hell. —Literally, If I make Sheôl my bed. (For the thought see Amos 9:2, and compare to Proverbs 15:11; Job 26:6).

This conviction that the underworld was not exempt from the vigilance and even from the visitation of Jehovah makes an advance in thought from Psalm 6:5 (where see Note), etc., where death is viewed as cutting off the Hebrew altogether from his relation to the Theocracy.