Gregory the Dialogist

Ver. 27. Fatness hath covered his face. For the sight is in the face, wherein too is the first more honourable part of the body. Therefore the best of the mind is not unjustly denoted by the face, which wherever we turn it, there we see. And so 'fatness covers the face,' in that the earnestly coveted abundance of earthly good things presses down the eyes of the mind, and that which should be honourable in them, it makes foul in the eyes of God, in that it weighs it to the earth with a multitude of concerns. …

Morals on the Book of Job, Book XII ↗

Thomas Aquinas

Pride usually arises from an abundance of temporal goods, and so the text continues, "he is furnished with a fat neck," by acting proud against God. For fat is caused by an abundance of humors and so is an image for an abundance of temporal goods. Just as humility is the first stage of wisdom, so pride is an obstacle to wisdom and so the text continues, "Thick darkness covered his face," because the covering of his face is an image for the impediment to knowledge. …

Commentary on Job ↗