Mark 3:12-17

But he gave them strict orders not to tell others about him. Jesus went up on a mountainside and called to him those he wanted, and they came to him. He appointed twelve that they might be with him and that he might send them out to preach and to have authority to drive out demons. These are the twelve he appointed: Simon (to whom he gave the name Peter), James son of Zebedee and his brother John (to them he gave the name Boanerges , which means “sons of thunder”)