Albert Barnes on Matthew 11:6

And blessed is he, etc. The word offence means a stumbling-block. Mt 5:29. This verse might be rendered, "Happy is he to whom I shall not prove a stumbling-block!" That is, happy is he who shall not take offence at my poverty and lowliness of life, so as to reject me and my doctrine. Happy is he who can, notwithstanding that poverty and obscurity, see the evidence that I am the Messiah, and follow me. It is not improbable that John wished Jesus publicly to proclaim himself as the Christ, instead of seeking retirement. Jesus replied that he gave sufficient evidence of that by his works; that a man might discover it if he chose; and that he was blessed who would seek that evidence, and embrace him as the Christ, in spite of his humble manner of life.

(e) "not be offended in me" Is 8:14,15, 1Cor 1:22,23, 1Pet 2:8