THE GOSPEL ACCORDING TO MATTHEW - Chapter 20 - Verse 21

Verse 21. Grant that these my two sons may sit, etc. They were still looking for a temporal kingdom. They expected that he would reign on the earth with great pomp and glory. They expected that he would conquer as a prince and a warrior. They wished to be distinguished in the day of his triumph. To sit on the right and left hand of a prince was a token of confidence, and the highest honour granted to his friends, 1 Ki 2:19; Ps 110:1; 1 Sa 20:25.

The disciples here had no reference to the kingdom of heaven, but only to the kingdom which they supposed he was about to set up on the earth.