Mark 9:34-37

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.”