Isaiah 6:2-4 New Revised Standard Version (NRSV)
2 Seraphs were in attendance above him; each had six wings: with two they covered their faces, and with two they covered their feet, and with two they flew. 3 And one called to another and said:
“Holy, holy, holy is the Lord of hosts;
4 The pivots[a] on the thresholds shook at the voices of those who called, and the house filled with smoke.