The Return of the King
"No, Sam!" said Frodo. "Do not kill him even now. For he has not hurt me. And in any case I do not wish him to be slain in this evil mood. He was great once, of a noble kind that we should not dare to raise our hands against. He is fallen, and his cure is beyond us; but I would still spare him, in the hope that he may find it."
Saruman rose to his feet, and stared at Frodo. There was a strange look in his eyes of mingled wonder and respect and hatred. "You have grown, Halfling," he said. "Yes, you have grown very much. You are wise, and cruel. You have robbed my revenge of sweetness, and now I must go hence in bitterness, in debt to your mercy. I hate it and you! Well, I go and I will trouble you no more. But do not expect me to wish you health and long life. You will have neither. But that is not my doing. I merely foretell." (6.8.228-9)