Matthew 12:34
34 pYou brood of vipers! How can you speak good, qwhen you are evil? rFor out of the abundance of the heart the mouth speaks.
James 3:6
6 And ithe tongue is a fire, a world of unrighteousness. The tongue is set among our members, jstaining the whole body, setting on fire the entire course of life,1 and set on fire by hell.2