“You won’t be killing anyone else tonight,” said Harry as they circled, and stared into each other’s eyes, green into red. “You won’t be able to kill any of them ever again. Don’t you get it? I was ready to die to stop you from hurting these people —”

“But you did not!”

“— I meant to, and that’s what did it. I’ve done what my mother did. They’re protected from you. Haven’t you noticed how none of the spells you put on them are binding? You can’t torture them. You can’t touch them. You don’t learn from your mistakes, Riddle, do you?”

“You dare —”

“Yes I dare,” said Harry. “I know things you don’t know, Tom Riddle. I know lots of important things that you don’t. Want to hear some, before you make another big mistake?”

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