Matthew 3:7

But when he saw many of the pharisees and sadducees coming to his baptism, he said unto them, O generation of vipers, who hath warned you to flee from the wrath to come?

Matthew 23:33

how can ye escape the damnation of hell?

Romans 3:13

Their throat is an open sepulchre: with their tongues they have used deceit; the poison of asps is under their lips:

James 3:8

but the tongue can no man tame; it is an unruly evil, full of deadly poison.

Treasury of Scripture Knowledge

Summary

Their poison is like the poison of a serpent: they are like the deaf adder that stoppeth her ear;

Bible References

Poison

Romans 3:13
Their throat is an open sepulchre: with their tongues they have used deceit; the poison of asps is under their lips:
James 3:8
but the tongue can no man tame; it is an unruly evil, full of deadly poison.