35 And James and John, the sons of Zebedee, came up to him and said to him, "Teacher, we want you to do for us whatever we ask of you." 36 And he said to them, "What do you want me to do for you?" 37 And they said to him, "Grant us to sit, one at your right hand and one at your left, in your glory." 38 Jesus said to them, "You do not know what you are asking. Are you able to drink the cup that I drink, or to be baptized with the baptism with which I am baptized?" 39 And they said to him, "We are able." And Jesus said to them, "The cup that I drink you will drink, and with the baptism with which I am baptized, you will be baptized, 40 but to sit at my right hand or at my left is not mine to grant, but it is for those for whom it has been prepared." 41 And when the ten heard it, they began to be indignant at James and John. 42 And Jesus called them to him and said to them, "You know that those who are considered rulers of the Gentiles lord it over them, and their great ones exercise authority over them. 43 But it shall not be so among you. But whoever would be great among you must be your servant, 44 and whoever would be first among you must be slave of all. 45 For even the Son of Man came not to be served but to serve, and to give his life as a ransom for many."
Mark 10:35–45 (ESV)