Then said he to the multitude that came forth to be baptized of him, O generation of vipers…
It is related of John Wesley that, preaching to an audience of courtiers and noblemen, he used the "generation of vipers" text, and flung denunciation right and left. "That sermon should have been preached at Newgate," said a displeased courtier to Wesley on passing out. "No," said the fearless apostle; "my text there would have been, 'Behold the Lamb of God, which taketh away the sin of the world!'"
(Baxendale's "Anecdotes. ")
Parallel VersesKJV: 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?