Revelation 4:6; Revelation 4:8

6 and before the throne there was something like a sea of glass, like crystal; and in the center and around the throne, four living creatures full of eyes in front and behind.

8 And the four living creatures, each one of them having six wings, are full of eyes around and within; and day and night they do not cease to say, "HOLY, HOLY, HOLY is THE LORD GOD, THE ALMIGHTY, WHO WAS AND WHO IS AND WHO IS TO COME."