[Essex]

alatar,

look at post #27 above which shows the text. Here is an expanded version. Trust me, it's from the book.

'Come back, Saruman!' said Gandalf in a commanding voice. To the amazement of the others, Saruman turned again. and as if dragged against his will, he came slowly back to the iron rail, leaning on it, breathing hard. His face was lined and shrunken. His hand clutched his heavy black staff like a claw.
'I did not give you leave to go,' said Gandalf sternly. 'I have not finished. You have become a fool, Saruman, and yet pitiable. You might still have turned away from folly and evil, and have been of service. But you choose to stay and gnaw the ends of your old plots. Stay then! But I warn you. you will not easily come out again. Not unless the dark hands of the East stretch out to take you. Saruman!' he cried, and his voice grew in power and authority. 'Behold, I am not Gandalf the Grey, whom you betrayed. I am Gandalf the White, who has returned from death. You have no colour now, and I cast you from the order and from the Council.'
He raised his hand, and spoke slowly in a clear cold voice. 'Saruman, your staff is broken.' There was a crack, and the staff split asunder in Saruman's hand, and the head of it fell down at Gandalf's feet. 'Go!' said Gandalf. With a cry Saruman fell back and crawled away

This shows that it was the power of his voice (and hand if you must) that broke his sword.

IMO, what one needs to do when analysing a scene, is to think WHY Tolkien wrote it this way. What, IMO, he is doing here by writing that Gandalf raised his hand and used his voice is EXPLICITLY showing that Gandalf DOES NOT NEED TO USE HIS STAFF to cast Saruman from the Order. (If he wanted to show Gandalf was chanelling power or gaining power from his staff he would have written "raised his staff' instead of 'raised his hand') Indeed, at the start of the passage, all Gandalf needed to haul Saruman back was the power of his Voice. Tolkien is showing in this scene that Gandalf can break Saruman's staff and cast him from the Order with his own power, simple and direct, and not chanelling through any object.

PS Gandalf's staff is mentioned ONCE by Tolkien in the whole of the Voice of Saruman Chapter, and just as a door knocker!

Gandalf stood before the door of Orthanc and beat on it with his staff. It rang with a hollow sound. 'Saruman, Saruman!' he cried in a loud commanding voice. 'Saruman come forth!'