Jamieson, Fausset and Brown on Job 22:30

30. island--that is, "dwelling." But the Hebrew expresses the negative (1Sa 4:21); translate "Thus He (God) shall deliver him who was not guiltless," namely, one, who like Job himself on conversion shall be saved, but not because he was, as Job so constantly affirms of himself, guiltless, but because he humbles himself (Job 22:29); an oblique attack on Job, even to the last.

and it--Rather, "he (the one not heretofore guiltless) shall be delivered through the purity (acquired since conversion) of thy hands"; by thy intercession (as Ge 18:26, &c.). [Maurer]. The irony is strikingly exhibited in Eliphaz unconsciously uttering words which exactly answer to what happened at last: he and the other two were "delivered" by God accepting the intercession of Job for them (Job 42:7, 8).