Revelation 4:6-8 New Revised Standard Version (NRSV)
6 and in front of the throne there is something like a sea of glass, like crystal.
Around the throne, and on each side of the throne, are four living creatures, full of eyes in front and behind: 7 the first living creature like a lion, the second living creature like an ox, the third living creature with a face like a human face, and the fourth living creature like a flying eagle. 8 And the four living creatures, each of them with six wings, are full of eyes all around and inside. Day and night without ceasing they sing,
“Holy, holy, holy,