Jamieson, Fausset and Brown on Job 8:4

4. If--Rather, "Since thy children have sinned against Him, and (since) He has cast them away (Hebrew, by the hand of) for their transgressions, (yet) if thou wouldst seek unto God, &c., if thou wert pure, &c., surely [even] now He would awake for thee." Umbreit makes the apodosis to, "since thy children," &c., begin at "He has cast them away." Also, instead of "for," "He gave them up to (literally, into the hand of) their own guilt." Bildad expresses the justice of God, which Job had arraigned. Thy children have sinned; God leaves them to the consequence of their sin; most cutting to the heart of the bereaved father.