John Wesley on Job 2:8

Scrape - This he did not with soft linen clothes, either because he had not now a sufficient quantity of them; or because therein he must have had the help of others who abhorred to come near him. Nor with his own hands or fingers, which were also ulcerous, and so unfit for that use; but with potsherds, either because they were next at hand, and ready for his present use; or in token of his deep humiliation under God's hand, which made him decline all things that favoured of tenderness and delicacy. Heb. in dust or ashes, as mourners used to do. If God lay him among the ashes, there he will contentedly sit down. A low spirit becomes low circumstances, and will help to reconcile us to them.