Revelation 4:6-8

6In front of the throne, there was something like a sea of glass as clear as crystal. In the center near the throne and around the throne were four living creatures covered with eyes in front and in back.

7The first living creature was like a lion, the second was like a young bull, the third had a face like a human, and the fourth was like a flying eagle.

8Each of the four living creatures had six wings and were covered with eyes, inside and out. Without stopping day or night they were singing, “Holy, holy, holy is the Lord God Almighty, who was, who is, and who is coming.”