I’ve been reading the commentary of the early church fathers on scripture (Ancient Christian Commentary on Scripture, Intervarsity Press).
I forget now which bishops commented on John the Baptist, but I recalled how they marvelled over how he was the greatest of the Old Testament prophets: He did not foretell the coming of the Messiah, he actually pointed him out saying, in effect, there he is! the lamb of God who takes away the sins of the world.
They go on to say how John was filled with the Holy Spirit in his mother’s womb, such that he stirred when Mary (and Jesus) came into her presence.
All this being said, it puzzles me why somewhat later, I think when John is in prison, he sends his disciples to question Jesus who he really is, should they look for another? The tendency of scripture scholars is to look for explanations that would tend to harmonize different verses, seemingly contradictory verses. I don’t recall if there is any commentary that harmonizes John’s doubts about Jesus.
There IS the patristic observation that John represents the Old Testament, and his imprisonment symbolizes the end, the sequestering, of the Old Testament, and even the ‘death’ of the OT with his physical death.