Luke 3:7

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.

(cont. Eunom. lib. 2.) Now it may be observed, that the following words natus and filius are spoken of animals, but genimen may be said of the fœtus before it is formed in the womb; the fruit of the palm trees is also called genimina, but that word is very seldom used with respect to animals, and when it is, always in a bad sense.

We see these men through the compassion of God, inspired with prudence to seek repentance of their crimes, dreading with wise devotion the terror of the judgment to come. Or perhaps, according to the precept, Be ye wise as serpents, (Matt. 10:16.) they are shown to have a natural prudence, who perceive what is coming, and earnestly desire help, though they still forsake not what is hurtful.

(Hom. in Matt. 10.) The dweller in the wilderness, when he saw all the people of Palestine standing round him and wondering, bent not beneath the weight of such respect, but rose up against them and reproved them. (Hom. in Gen. 12.) The holy Scripture often gives the names of wild beasts to men, according to the passions which excite them, calling them sometimes dogs because of their impudence, horses on account of their lust, asses for their folly, lions and panthers for their ravening and wantonness, asps for their guile, serpents and vipers for their poison and cunning; and so in this place John calls the Jews a generation of vipers. (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.

(in Hom. 20, in Ev.) Because the Jews hated good men, and persecuted them, following the steps of their carnal parents, they are by birth the poisonous sons, as it were, of poisonous or sorcerous parents. But because the preceding verse declares that at the last judgment Christ shall be seen by all flesh, it is rightly added, Who hath warned you to flee from the wrath to come? The wrath to come being the awarding of final punishment.