Albert Barnes on Matthew 11:2

The account contained in this chapter of Matthew to the 19th verse, is found, with no material variation, in Lk 7:18-35. John was in prison. Herod had thrown him into confinement, on account of John's faithfulness in reproving him for marrying his brother Philip's wife. See Mt 14:3,4.

It is not certainly known why John sent to Jesus. It might have been to satisfy his disciples that Jesus was the Messiah; or he might have been desirous of ascertaining for himself whether this person of whom he heard so much was the same one whom he had baptized, and whom he knew to be the Messiah. See Jn 1:29.

(d) "Now when John" Lk 7:18