Isaiah 6:4 WEB

²  Above him stood the seraphim. Each one had six wings. With two he covered his face. With two he covered his feet. With two he flew.

³  One called to another, and said, 'Holy, holy, holy, is Yahweh of Hosts! The whole earth is full of his glory!'

⁴  The foundations of the thresholds shook at the voice of him who called, and the house was filled with smoke.

⁵  Then I said, '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 my eyes have seen the King, Yahweh of Hosts!'

⁶  Then one of the seraphim flew to me, having a live coal in his hand, which he had taken with the tongs from off the altar.