The deep reason for Job’s unrest is that he cannot understand his sufferings. He cannot understand why a believer, a man of godliness and piety, suffers with such mind-numbing intensity. This inexplicable trouble shakes the foundations of his moral and ordered universe. It is for this reason he cannot and will not rest until he has found some resolution to this cosmic question.
 At heart human rest is rooted in the rest of God when he looks on a completed and good creation (Genesis 2:1–3). Rest is predicated on cosmic order, a creation in which there are proper boundaries, in which virtue is rewarded and vice punished, in which there is justice and in which goodness triumphs. Job longs to share that rest with God. At the moment his experience is the polar opposite. So he ends his speech with a desperate question.
-Christopher Ash, Job