‘Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips:  for mine eyes have seen the King, the Lord of hosts.’
—Isaiah 6:5

‘O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.’
—Matthew 12:34