What did the seraph put on Isaiah's mouth in chapter 6?
For I am come to set a man at variance against his father, and the daughter against her mother, and the daughter in law against her mother in law. And a man's foes shall be they of his own household. Matthew 10:35
Then flew one of the seraphims unto me, having a live coal in his hand, which he had taken with the tongs from off the altar:
And he laid it upon my mouth. Isaiah 6:6