John Gill's Exposition of the Whole Bible
Job 3:13
For now should I have lain still, and been quiet,.... Signifying, that if the above had been his case, if he had died as soon as born, or quickly after, then he would have been laid in the grave, where he would have lain as still as on a bed; for such is the grave to dead bodies as a bed is to those that lie down and sleep upon it; a place of ease and quiet, where there is freedom from all care and thought, from all trouble, anxiety, and distress; nay, more so than on a bed, where there is often tossing to and fro, and great disquietude, but none to the body in the grave, that is still and silent, where there is no uneasiness nor disturbance, see Job 17:13;
I should have slept; soundly and quietly, which persons do not always upon their beds; sometimes they cannot sleep at all, and when they do, they are frequently distressed with uneasy thoughts, frightful dreams, and terrifying visions, Job 4:13; but death is a sound sleep until the resurrection morn, which Job had knowledge of, and faith in, and so considered the state of the dead in this light; death is often in Scripture expressed by sleeping, Daniel 12:2; which refers not to the soul, which in a separate state is active and vigorous, and always employed; but to the body, which, as in sleep, so in death, is deprived of the senses, and the exercise of them; on which account there is a great likeness between sleep and death, and out of which a man awakes brisk and cheerful, as the saints will at the time of their resurrection, which will be like an awaking out of sleep:
then had I been at rest; from all toil and labour, from all diseases and pains of body, from all troubles of whatsoever kind, and particularly from those he now laboured under, Job 3:17.