Revelation 4:8

And 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, is the Lord God the Almighty, who was and who is and who is to come.

Six wings ... The use of these, as indicated in Isaiah 6, was: two covered the face (reverence), two covered the feet (humility), and "with twain did he fly." No such employment of the wings is mentioned here.

It would appear that the big point of this was properly ascertained by Barnes:

All these creatures pay ceaseless homage to God, whose throne they are represented as supporting; emblematic of the fact that all the operations of the divine government do, in fact, promote his glory, and, as it were, render him praise.[43]

Holy, holy, holy ... In commentaries, now and then, one finds this referred to as the Trisagion; but the designation is not accurate.

The Trysagion is the hymn which is sung, according to the rite of Constantinople, in connection with the Little Entrance .... In the Roman liturgy, it is sung on only one day of the year, Good Friday, in the special office called the Reproaches.[44]

Who was and who is and who is to come ... On this reference to Exodus 3:14, see comment on similar words in Revelation 1:4,8.

[43] Albert Barnes, op. cit., p. 107.

[44] A. Plummer, op. cit., p. 147.