In Isaiah 6 the prophet records his “commissioning” by God, which occurs in a vision in which seraphs (angels) are singing praise to God. Isaiah is so awestruck that he cries out “Woe is me!” lamenting that he is an impure man living among impure people.
One of the seraphs takes a live coal from the altar, touches Isaiah’s mouth, and declares him purified. Then God asks, “Whom shall I send?” The prophet replies, “Here am I! Send me.”