Albert Barnes Commentary Mark 10:14

"But when Jesus saw it, he was moved with indignation, and said unto them, Suffer the little children to come unto me; forbid them not: for to such belongeth the kingdom of God." — Mark 10:14 (ASV)

Saw it. Saw the conduct of his disciples.

Was much displeased. Because:

1. It was a pleasure to him to receive and bless little children.
2. They were doing what they were not commanded to do—interfering in a case where it was evidently improper.