Mark 9:30-41 ESV
They went on from there and passed through Galilee. And he did not want anyone to know, for he was teaching his disciples, saying to them, “The Son of Man is going to be delivered into the hands of men, and they will kill him. And when he is killed, after three days he will rise.” But they did not understand the saying, and were afraid to ask him.
And they came to Capernaum. And when he was in the house he asked them, “What were you discussing on the way?” But they kept silent, for on the way they had argued with one another about who was the greatest. And he sat down and called the twelve. And he said to them, “If anyone would be first, he must be last of all and servant of all.” And he took a child and put him in the midst of them, and taking him in his arms, he said to them, “Whoever receives one such child in my name receives me, and whoever receives me, receives not me but him who sent me.”
John said to him, “Teacher, we saw someone casting out demons in your name, and we tried to stop him, because he was not following us.” But Jesus said, “Do not stop him, for no one who does a mighty work in my name will be able soon afterward to speak evil of me. For the one who is not against us is for us. For truly, I say to you, whoever gives you a cup of water to drink because you belong to Christ will by no means lose his reward.
ESV: English Standard Version 2016