Brood of vipers is the same expression used by John the Baptist in 3.7. Matthew evidently intends to make a close correlation between the message and fate of John the Baptist and that of Jesus. Serpents is a different word in Greek than vipers, but there is no distinction in meaning; the use of two parallel expressions represents a stylistic feature of Hebraic Greek. Translators do not necessarily have to use the name of a member of the viper family if this snake is not known. And if to call someone a snake is not such a terrible thing, translators may have to modify the words slightly to something like “You treacherous and dangerous snakes!” or “How treacherous and dangerous you are, just like a family of snakes!”

How are you to escape being sentenced to hell?: as more than one commentator notes, this is in the style of a saying derived from Jewish apocalyptic literature. Hell is the same word discussed at 5.22. It may be more effective to shift the rhetorical question to an affirmation: “You cannot expect to escape from being sentenced to hell!” Moreover, effective translation may require the explicit mention of who it is that will condemn them to hell: “God is certain to condemn you to hell! You cannot hope to escape!”

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .