Whom, though I were righteous, yet would I {k} not answer, but I would make supplication to my judge.

(k) Meaning, in his own opinion, signifying that man will sometimes flatter himself to be righteous which before God is an abomination.

Wesley's Notes

9:15 Tho' - Though I were not conscious to myself of any sin. Would not - I durst not undertake to plead my cause against him; or maintain my integrity before him, because he knows me better than I know myself. Supplication - That he would judge favourably of me and my cause, and not according to the rigour of his justice.

Jamieson-Fausset-Brown Bible Commentary

15. (Job 10:15). Though I were conscious of no sin, yet I would not dare to say so, but leave it to His judgment and mercy to justify me (1Co 4:4).

Matthew Henry's Concise Commentary

9:14-21 Job is still righteous in his own eyes, ch. 32:1, and this answer, though it sets forth the power and majesty of God, implies that the question between the afflicted and the Lord of providence, is a question of might, and not of right; and we begin to discover the evil fruits of pride and of a self-righteous spirit. Job begins to manifest a disposition to condemn God, that he may justify himself, for which he is afterwards reproved. Still Job knew so much of himself, that he durst not stand a trial. If we say, We have no sin, we not only deceive ourselves, but we affront God; for we sin in saying so, and give the lie to the Scripture. But Job reflected on God's goodness and justice in saying his affliction was without cause.