John Chrysostom
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,
(Hom. in Matt. 11.) Now they say that the female viper kills the male in copulation, and the fœtus as it increases in the womb kills the mother, and so comes forth into life, bursting open the womb in revenge as it were of its father’s death; the viper progeny therefore are parricides. Such also were the Jews, who killed their spiritual fathers and teachers. But what if he found them not sinning, but beginning to be converted? He ought not surely to rebuke them, but to comfort them. We answer, that he gave not heed to those things which are outward, for he knew the secrets of their hearts, the Lord revealing them to him; for they vaunted themselves too much in their forefathers. Cutting therefore at this root, he calls them a generation of vipers, not indeed that he blamed the Patriarchs, or called them vipers.