But to sit on my right hand and on my left hand is not mine to give; but it shall be given to them for whom it is prepared.
All Commentaries on Mark 10:40 Go To Mark 10
Theophylact of Ochrid
AD 1107
Now the above mentioned disciples thought that He was going up to Jerusalem, to reign there, and then to suffer what He had foretold. And with these thoughts, they desired to sit on the right hand and the left hand. Wherefore there follows: “They said unto Him, Grant unto us that we may sit, one on Thy right hand, the other on Thyleft hand, in Thy glory.”
It will not be as ye think, that I am to reign as a temporal king in Jerusalem, but all these things, that is, these which belong to My kingdom, are beyond your understanding; for to site on My right hand is so great a thing that it surpasses the Angelic orders.