Greatness is service: The passage begins with Jesus’ third prediction of his betrayal, death, and resurrection. His advice—to be the servants and the last of all—is not easy to accept.
The mother of James and John place before Jesus their request. To sit at the right hand of a king means to have the highest place; the place at his left hand is the next best. Their timing, right after Jesus’ detailed forecast of his death, is shockingly insensitive and its demand outrageous.
Jesus patiently tells the mother she does not know what she is asking. He asks her sons if they could drink his cup of suffering. Envisioning a great royal court that they associate with the Messiah, they brashly say they can. Unwittingly, they will to live up to their claim. After Jesus’ death, James will be the first of the apostles to suffer martyrdom (Acts 12:2): he is beheaded in Jerusalem. Later John, the only apostle to die a natural death, is, according to Tertullian, put into a cauldron of boiling oil; miraculously escaping, he is scourged and afterwards exiled to Patmos (Rv 1:9), where he eventually dies.
For God, success is judged not by how much we can get out of life, but how much we put into it.