1 Samuel 26:21 - Joseph Benson’s Commentary on the Old and New Testaments

Then said Saul, I have sinned This second instance of David's tenderness wrought more upon Saul than the former. He owns himself melted, and quite overcome by David's kindness to him. My soul was precious in thine eyes which I thought had been odious. He acknowledges he had done very ill to persecute him: I have acted against God's law; I have sinned: and against my own interest; I have played the fool In pursuing thee as an enemy, who wast, indeed, one of my best friends. And herein I have erred exceedingly Have wronged both thee and myself. Nothing can be more full and ingenuous than this confession. God surely now touched his heart. And he promises to persecute him no more: nor does it appear that he ever attempted it afterward.