Isaiah 6:2

6:2 Seraphs stood over him; each one had six wings. With two wings they covered their faces, with two they covered their feet, and they used the remaining two to fly.

Isaiah 6:6-7

6:6 But then one of the seraphs flew toward me. In his hand was a hot coal he had taken from the altar with tongs. 6:7 He touched my mouth with it and said, “Look, this coal has touched your lips. Your evil is removed; your sin is forgiven.”