Revelation 4:6, 8

Before the throne there was a sea of glass, like crystal. And in the midst of the throne, and around the throne, were four living creatures full of eyes in front and in back.

The four living creatures, each having six wings, were full of eyes around and within. And they do not rest day or night, saying: “Holy, holy, holy, Lord God Almighty, Who was and is and is to come!”