What does Matthew 20:20-21 mean?

20 Then came to him the mother of Zebedee’s children with her sons, worshipping him, and desiring a certain thing of him. 21 And he said unto her, What wilt thou? She saith unto him, Grant that these my two sons may sit, the one on thy right hand, and the other on the left, in thy kingdom. (Matthew 20:20-21 KJV)

Spurgeon’s Commentary on Matthew

vrs 20-21  While the mind of Jesus was occupied with his humiliation and death, his followers were thinking of their own honor and ease. Alas, poor human nature! The mother of Zebedee’s children only spoke as others felt. She, with a mother’s love, sought eminence, and even preeminence, for her sons; but the fact that the other disciples were displeased showed that they were ambitious also. Doubtless, they wanted to fill the positions, that the mother of James and John craved for them. She approached the Savior reverently, worshipping him. Yet there was too much familiarity in her request to be granted an unnamed thing: desiring a certain thing of him. Our Lord here sets us the example of never promising in the dark. He said unto her, “What wilt thou?” Know what you promise before you promise. Great was this woman’s faith in the Lord’s ultimate victory and occasion to the throne, since she regards his enthronement as so certain, that she prays that her two sons should sit in his courts on his right and left hand. Was she aware of what our Lord had told his disciples? We half think so, for the words are,—Then came to him the mother of Zebedee’s children. If she knew and understood all that wont before, she was willing that her sons should share the lot of Jesus, both as to his cross and his crown; and this sets her petition in a bright light. Still, there was a good deal of a mother’s partiality in the request. See how she speaks of “these my two sons” with a touch of pride in her action. How grandly she describes the desired situation — “may sit the one on thy right hand, and the other on the left, in thy kingdom”! She had evidently very courtly notions of what the kingdom would ultimately become. In any case, her request had in it much of trust, and much of loyal union to Christ, though somewhat. also of self. We need not censure her; but we may question ourselves as to whether we think as much of our Lord as she did.