Revelation 4:6-8

6And before the throne was something like a sea of glass, as clear as crystal. In the center, around the throne, were four living creatures, covered with eyes in front and back. 7The first living creature was like a lion, the second like a calf, the third had a face like a man, and the fourth was like an eagle in flight. 8And each of the four living creatures had six wings and was covered with eyes all around and within. Day and night they never stop saying: