Origen
Catena Aurea · Lukasevangelium 3
Then said he to the multitude that came forth to be baptized of him, O generation of vipers, who hath warned you to flee from the wrath to come? Bring forth therefore fruits worthy of repentance, and begin not to say within yourselves, We have Abraham to our father: for I say unto you, That God is able of these stones to raise up children unto Abraham. And now also the axe is laid unto the root of the trees: every tree therefore which bringeth not forth good fruit is hewn down, and cast into the fire,
No one that remains in his old state, and forsakes not his old habits and practices, can rightly come to be baptized; whoever then wishes to be baptized, let him go forth. Hence are those words significantly spoken, And he said unto the multitude that went forth to be baptized of him. To the multitudes then who are going forth to the laver of baptism, He speaks the following words, for if they had already gone forth, He would not have said, O generation of vipers.