Revelation 4:6-8

6and before the throne, as it were a sea of glass like unto crystal; and in the midst of the throne, and round about the throne, four living creatures full of eyes before and behind. 7And the first creature was like a lion, and the second creature like a calf, and the third creature had a face as of a man, and the fourth creature was like a flying eagle. 8And the four living creatures, having each one of them six wings, are full of eyes round about and within: and they have no rest day and night, saying,

Holy, holy, holy, isthe Lord God, the Almighty, who was and who is and who is to come.