Charles H. Spurgeon on Psalms 102:9

For I have eaten ashes like bread. He had so frequently cast ashes upon his head in token of mourning, that they had mixed with his ordinary food, and grated between his teeth when he ate his daily bread. One while he forgot to eat, and then the fit changed, and he ate with such a hunger that even ashes were devoured. Grief has strange moods and tenses. And mingled my drink with weeping. His drink became as nauseous as his meat, for copious showers of tears had made it brackish. This is a telling description of all-saturating, all-embittering sadness, —and this was the portion of one of the best of men, and that for no fault of his own, but because of his love to the Lord's people. If we, too, are called to mourn, let us not be amazed by the fiery trial as though some strange thing had happened unto us. Both in meat and drink we have sinned; it is not therefore wonderful if in both we are made to mourn.