Ye serpents, ye generation of vipers; γεννη ìματα ἐχιδνῶν: offspring of vipers. Our Lord repeats the Baptist's denunciation (Matthew 3:7). They were of devilish nature, inherited from their very birth the disposition and character of Satan.
So Christ said on another occasion, "Ye are of your father the devil, and the lusts of your father it is your will to do. He was a murderer from the beginning, and stood not in the truth" (John 8:44).
How can ye escape? πῶς φυ ìγητε; the deliberative conjunctive, How shall ye escape? Quo mode fugietis? (Vulgate). There is no emphasis on "can" in the Authorized Version. What hope is there now of your repentance?
Can anything soften the hardness of your hearts? The Baptist had spoken more hopefully, "Who hath warned you to flee from the wrath to come?" But now the day of grace is past; the sin against the Holy Ghost is committed; there remaineth only the fearful looking for of judgment.
The damnation of hell; literally, the judgment of Gehenna; judicio Gehennae (Vulgate); i.e. the sentence that condemns to eternal death (Matthew 5:22). The phrase is common in the rabbinical writings (see Lightfoot).
"Before sinning, we ought to fear lest it be the filling up; after sinning, we should trust in a truly Christian hope that it is not, and repent. This is the only means to escape the damnation of hell; but how rare is this grace after a pharisaical life!"
(Quesnel). Hypocrisy is a bar to repentance.