Mark 9:33-35

Then they came to Capernaum. And as soon as Jesus was inside the house, he asked his disciples, “What were you arguing about on the way here?” No one said a word, because they had been arguing about which one of them was the greatest. Jesus sat down, called the twelve disciples to come around him, and said to them, “If anyone wants to be first, he must be content to be last and become a servant to all.”