Then the mother of the sons of Zebedee came to him with her sons, and kneeling before him, she asked a favor of him.
And he said to her, "What do you want?" She said to him, "Declare that these two sons of mine will sit, one at your right hand and one at your left, in your kingdom."
But Jesus answered, "You do not know what you are asking. Are you able to drink the cup that I am about to drink?" They said to him, "We are able."
References for Matthew 20:22
He said to them, "You will indeed drink my cup, but to sit at my right hand and at my left, this is not mine to grant, but it is for those for whom it has been prepared by my Father."
When the ten heard it, they were angry with the two brothers.
But Jesus called them to him and said, "You know that the rulers of the Gentiles lord it over them, and their great ones are tyrants over them.
It will not be so among you; but whoever wishes to be great among you must be your servant,
and whoever wishes to be first among you must be your slave;
just as the Son of Man came not to be served but to serve, and to give his life a ransom for many."