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.
Revelation 4:6
Surrounding context
4:5 And from the throne proceeded lightnings, thunderings, and voices. Seven lamps of fire were burning before the throne, which are the seven Spirits of God.
4:6 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.
4:7 The first living creature was like a lion, the second living creature like a calf, the third living creature had a face like a man, and the fourth living creature was like a flying eagle.