Catena Aurea on Luke 9:7–9: Augustine of Hippo

Now Luke, though he keeps the same order in his narrative with Mark, docs not oblige us to believe that the course of events was the same. In these words too, Mark testifies only to the fact that others (not Herod) said that John had risen from the dead, but since Luke has mentioned Herod’s perplexity, we must suppose either that after that perplexity, he confirmed in his own mind what was said by others, since he says to his servants, (as Matthew relates,) This is John the Baptist, he is risen from the dead, or these words of Matthew must have been uttered so as to signify that he was still doubting.