John the Baptist had also called the Pharisees a brood of vipers
(Matthew 3:7), showing their deadliness and descent from Satan, the ancient serpent
(Revelation 12:9; Revelation 20:2). Jesus repeats this phrase to show the root of their opposition. Like those who had refused John’s baptism, the Pharisees wanted to escape God’s coming wrath without true repentance, shown in their blasphemy against Jesus. He made not only a moral judgment on their outward conduct but a religious judgment on their rejection of God’s grace. Quoting John’s sharp words unmasks them as hostile, because they first rejected John’s baptism for the forgiveness of sins, and now show themselves as enemies of the One who came after him. Yet Matthew 12:34 shows a way back: changing their judgment of John and his preaching, and in so doing returning to Jesus.
John the Baptist had already called the Pharisees a brood of vipers
(Matthew 3:7). A viper is a dangerous and poisonous snake, and the expression brood of vipers
or offspring of snakes
can also suggest descent from Satan, the ancient serpent
(Revelation 12:9; Revelation 20:2).1
Jesus repeats this pointed expression to expose the true root of their opposition. Like those who had earlier refused John’s baptism, the Pharisees wanted to escape God’s coming wrath without true repentance. Their blasphemy against Jesus flowed from the same hardened unbelief. This was not merely a moral judgment on their outward conduct but a religious judgment on their rejection of God’s grace. By quoting John’s sharp words, Jesus unmasks them as hostile opponents who, having rejected John’s baptism for the forgiveness of sins, now show themselves as enemies of the One who came after him. Yet even here, Matthew 12:34 leaves a way back: they must first change their judgment of John and his preaching, and in so doing return to Jesus.2
34 You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks.