She said to Him, "Grant that these two sons of mine may sit, one on Your right hand and the other on the left, in Your kingdom." 

But Jesus answered and said, "You do not know what you ask. Are you able to drink the cup that I am about to drink, and be baptized with the baptism that I am baptized with?

They said to Him, "We are able." 

So He said to them, "You will indeed drink My cup, and be baptized with the baptism that I am baptized with; but to sit on My right hand and on My left is not Mine to give, but it is for those for whom it is prepared by My Father."

Mt 20:21-23   (NKJV)