The hobbits of the villages had seen Saruman come out of one of the huts, and at once they came crow

The hobbits of the villages had seen Saruman come out of one of the huts, and at once they came crowding up to the door of Bag End. When they heard Frodo’s command, they murmured angrily:

‘Don’t let him go! Kill him! He’s a villain and a murderer. Kill him!’

Saruman looked round at their hostile faces and smiled. 'Kill him!’ he mocked. 'Kill him, if you think there are enough of you, my brave hobbits!’ He drew himself up and stared at them darkly with his black eyes. 'But do not think that when I lost all my goods I lost all my power! Whoever strikes me shall be accursed. And if my blood stains the Shire, it shall wither and never again be healed.’

The hobbits recoiled. But Frodo said: 'Do not believe him! He has lost all power, save his voice that can still daunt you and deceive you, if you let it. But I will not have him slain. It is useless to meet revenge with revenge: it will heal nothing. Go, Saruman, by the speediest way!’

'Worm! Worm!’ Saruman called; and out of a nearby hut came Wormtongue, crawling, almost like a dog. 'To the road again, Worm!’ said Saruman. 'These fine fellows and lordlings are turning us adrift again. Come along!’

Saruman turned to go, and Wormtongue shuffled after him. But even as Saruman passed close to Frodo a knife flashed in his hand, and he stabbed swiftly. The blade turned on the hidden mail-coat and snapped. A dozen hobbits, led by Sam, leaped forward with a cry and flung the villain to the ground. Sam drew his sword.

'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.’

–J.R.R. Tolkien, The Lord of the Rings: The Return of the King, “The Scouring of the Shire”