Though I am blameless, I have no concern for myself; I despise my own life.
What Job had said of man's utter inability to contend with God he here applies to himself, and in effect despairs of gaining his favour, which (some think) arises from the hard thoughts he had of God, as one who, having set himself against him, right or wrong, would be too hard for him.
Commenting on Job 9:14-21
This is one thing,.... Or "one thing there is" (x) in the world, as Jarchi adds; or "one measure", as the Targum, to good and bad men; one event alike to the righteous, and to the wicked, Ecc 9:2; so that, as others render it, "it is all one" (y), whether a man righteous and perfect, or whether he is not, he is equally liable...
Literally, here (and in Job 9:20), "I perfect! I should not know my soul! I would despise," [that is], "disown my life"; that is, Though conscious of innocence, I should be compelled, in contending with the infinite God, to ignore my own soul and despise my past life as if it were guilty [ROSENMULLER].