משלי טז:כז פירוש: רש״י

digs up evil In his heart, he plots evil.

and on his lips is a kind of searing fire The evil burns on his lips until he expresses it with his mouth and executes it.

a kind of searing fire Heb. צרבת burning, as in (Ezek. 21:3): “And all faces shall be scorched (ונצרבו) by it.”