Since I am already found guilty, why should I labor in vain?
Job here grows more and more querulous, and does not conclude this chapter with such reverent expressions of God's wisdom and justice as he began with. Those that indulge a complaining humour know not to what indecencies, nay, to what impieties, it will hurry them. The beginning of that strife with God is as the letting forth of water; therefore leave it off before it be meddled with.
Commenting on Job 9:25-35
If I wash myself with snow water,.... As it came from heaven, or flowed from the mountains covered with snow, as Lebanon, see Jer 18:14; or was kept in vessels for such use, as being judged the best for such a purpose; so it was used by the ancients (n), as being what whitens the skin, and strengthens the parts by contracting the pores, and...
The "if" is better omitted; I (am treated by God as) wicked; why then labor I in vain (to disprove His charge)? Job submits, not so much because he is convinced that God is right, as because God is powerful and he weak [BARNES].