When Ron offered the sword, however, Harry shook his head.

“No, you should do it.”

“Me?” said Ron, looking shocked. “Why?”

“Because you got the sword out of the pool. I think it’s supposed to be you.”

He was not being kind or generous. As certainly as he had known that the doe was benign, he knew that Ron had to be the one to wield the sword. Dumbledore had at least taught Harry something about certain kinds of magic, of the incalculable power of certain acts.

Harry Potter and the Deathly Hallows – J.K. Rowling