John the Apostle
John 1:29ESV·traditional attribution

The next day he saw Jesus coming toward him, and said, “Behold, the Lamb of God, who takes away the sin of the world!

John Calvin Reformed @genevareformer

29. The next day. There can be no doubt that John had already spoken about the manifestation of the Messiah; but when Christ began to appear, he wished that his announcement of him should quickly become known, and the time was now at hand when Christ would put an end to John’s ministry, as, when the sun is risen, the dawn suddenly disappears.

Matthew Henry Presbyterian @wholebiblehenry

We have in these verses an account of John's testimony concerning Jesus Christ, which he witnessed to his own disciples that followed him. As soon as ever Christ was baptized he was immediately hurried into the wilderness, to be tempted; and there he was forty days.

Commenting on John 1:29-36

John Gill Reformed Baptist @doctorgill

The next day John seeth Jesus coming unto him,.... Not to be baptized, for he had been baptized before by him. This seems to have been after Christ had been forty days in the wilderness, from whence he now returned, and came to attend on John's ministry; both to do honour to him, and that he might be made manifest by him; and this was...