Albert Barnes Commentary Matthew 20:24

"And when the ten heard it, they were moved with indignation concerning the two brethren." — Matthew 20:24 (ASV)

The ten heard it. That is, the ten other apostles.

They were moved with indignation. They were offended at their ambition, at their desire to be exalted above their brethren. The word "it" refers not to what Jesus said, but to their request. When the ten heard the request which they had made, they were indignant.