In Isaiah 6:3 the angels are not merely singing a song, they are “RESPONDING” to what they SEE…Lord show me your Glory…open my eyes!!!
Is. 6:1-3 1. …I saw the Lord sitting on a throne, high and lifted up, and the train of His robe filled the temple. 2. Above it stood seraphim… 3. And one cried to another and said: “Holy, holy, holy is the Lord of hosts; The whole earth is full of His Glory!”
The Gate Hub 