Harry Potter and the Chamber of Secrets - Pg 338

  Lucius Malfoy stood frozen, staring at the elf. Then he lunged at Harry.  "You've lost me my servant, boy!"   But 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," he said fiercely, pointing down at Mr. Malfoy. "You shall not touch Harry Potter. You shall go now."