In the year that King Uzziah died, I saw the Lord sitting upon a throne, high and lifted up; and the train of his robe filled the temple. Above him stood the seraphim. Each had six wings: with two he covered his face, and with two he covered his feet, and with two he flew. And one called to another and said: “Holy, holy, holy is the Lord of hosts; the whole earth is full of his glory.

Isaiah 6:1-3 (ESV)