Augustine of Hippo
Catena Aurea · Matthäusevangelium 3
In those days came John the Baptist, preaching in the wilderness of Judæa, And saying, Repent ye: for the kingdom of heaven is at hand. For this is he that was spoken of by the Prophet Esaias, saying, The voice of one crying in the wilderness, Prepare ye the way of the Lord, make His paths straight.
(De Cons. Ev. ii. 12.) The other Evangelists omit these words of John. What follows, This is He, &c. it is not clear whether the Evangelist speaks them in his own person, or whether they are part of John’s preaching, and the whole from Repent ye, to Esaias the prophet, is to be assigned to John. It is of no importance that he says, This is he, and not, I am he; for Matthew speaking of himself says, He found a man sitting at the toll-office; (Mat. 9:9.) not He found me. Though when asked what he said of himself, he answered, as is related by John the Evangelist, I am the voice of one crying in the wilderness.