Charles H. Spurgeon on Psalms 73:21

The holy poet here reviews his inward struggle and awards himself censure for his folly. His pain had been intense; he says, Thus my heart was grieved. It was a deep seated sorrow, and one which penetrated his inmost being. Alexander reads it, "My heart is soured." His spirit had become embittered; he had judged in a harsh, crabbed, surly manner. He had become atrabilious, full of black bile, melancholy, and choleric; he had poisoned his own life at the fountain head, and made all its streams to be bitter as gall. And I was pricked in my reins. He was as full of pain as a man afflicted with renal disease; he had pierced himself through with many sorrows; his hard thoughts were like so many calculi in his kidneys; he was utterly wretched and woebegone, and all through his own reflections. O miserable philosophy, which stretches the mind on the rack, and breaks it on the wheel! O blessed faith, which drives away the inquisitors, and sets the captives free!