One cried; rather, kept crying (comp. Revelation 4:8, "They rest not day and night, saying, Holy, holy, holy"). But the prophet scarcely goes so far; he describes only his vision—they did not rest while the vision was vouchsafed him.
Holy, holy, holy. The Church on earth has taken pattern by the Church above; and the "Trisagion" is ever being repeated in one part of the earth or another without ceasing: "Thou continuest holy, O thou Worship of Israel."
There is no attribute so essential to God as this. It is for his holiness, more than for anything else, that his creatures worship him. The triple repetition has been understood in all ages of the Church as connected with the doctrine of the Trinity.
Holy is he who has created us, and bidden us worship him in the beauty of holiness Holy is he who has redeemed us, and washed away our sins, and made us by profession holy! Holy is he who day by day sanctifies us, and makes us in very deed and truth, so far as we will permit him, holy!
The whole earth is full of his glory. Even in heaven the seraphic thoughts are turned to earth, and its relation to its Divine Creator is made the subject of angelic utterances. The lesson which they gather from their contemplation, even under all the miserable circumstances of the time, is a cheering one: "The whole earth is full of God's glory."
Men, whether they will it or not, are working out God's purposes, advancing his designs, accomplishing the ends that he desires (see Homiletics on Isaiah 5:25-29).