"Dobby shouted, 'You shall not harm Harry Potter!'
There was a loud bang, and Mr. Malfoy was thrown backward. He crashed down the stairs, three at a time, landing in a crumpled heap on the landing below. He got up, his face livid, and pulled out his wand, but Dobby raised a long, threatening finger.
'You shall go now,' [Dobby] said fiercely, pointing down at Mr. Malfoy. 'You shall not touch Harry Potter. You shall go now.'"
--Chamber of Secrets