Luke 9:49-50

49 John answered, "Master, we saw someone casting out demons in your name, and we tried to stop him, because he does not follow with us."
50 But Jesus said to him, "Do not stop him; for whoever is not against you is for you."

Luke 9:49-50 In-Context

47 But Jesus, aware of their inner thoughts, took a little child and put it by his side,
48 and said to them, "Whoever welcomes this child in my name welcomes me, and whoever welcomes me welcomes the one who sent me; for the least among all of you is the greatest."
49 John answered, "Master, we saw someone casting out demons in your name, and we tried to stop him, because he does not follow with us."
50 But Jesus said to him, "Do not stop him; for whoever is not against you is for you."
51 When the days drew near for him to be taken up, he set his face to go to Jerusalem.
52 And he sent messengers ahead of him. On their way they entered a village of the Samaritans to make ready for him;