John Gill's Exposition of the Whole Bible
Job 30:19
He hath cast me into the mire,.... As Jeremiah was literally; here it is to be understood in a figurative sense; not of the mire of sin, into which God casts none, men fall into it of themselves, but of the mire of affliction and calamity; see Psalms 40:2; and which Job here ascribes to God; and whereby he was in as mean, abject, and contemptible a condition, as if he had been thrown into a kennel, and rolled in it; and he speaks of it as an act of God, done with contempt of him, and indignation at him, as he apprehended it. Some Jewish writers e interpret it, "he taught me in the mire", or "it taught me"; his disease, his ulcers taught him to sit down in the mire, or in the midst of ashes, Job 2:8; but though this reading might admit of a good sense, as that Job was taught, as every good man is, many useful lessons in and by afflictions; yet it seems to be a sense foreign from the words:
and I am become like dust and ashes; a phrase by which Abraham expresses his vileness, meanness, and unworthiness in the sight of God,
Genesis 18:27; Job, through the force of his disease, looked like a corpse, or one half dead, and was crumbling and dropping into the dust of death and the grave, and looked livid and ash coloured; and even in a literal sense was covered with dust and ashes, when he sat among them, Job 2:8; though here it chiefly respects the miserable, forlorn, and contemptible condition in which he was.
e Vid. Jarchi Bar Tzemach in loc.