Matthew 11:6 - Ellicott's Commentary On The Whole Bible

Blessed is he. — The words at once confirm the view that the question which the messengers had brought came from the Baptist himself, and show how tenderly our Lord dealt with the impatience which it implied. A warning was needed, but it was given in the form of a beatitude which it was still open to him to claim and make his own. Not to find a stumbling-block in the manner in which the Christ had actually come, that was the condition of entering fully into the blessedness of His kingdom.