The phrase "Holy, holy, holy" appears in the Bible in two key places:
* Isaiah 6:3: This is part of Isaiah's vision of God in the temple. The seraphim (angelic beings) are crying out to one another: "Holy, holy, holy is the Lord Almighty; the whole earth is full of his glory.”
* Revelation 4:8: This passage describes the throne of God in heaven. The four living creatures around the throne are saying, "Holy, holy, holy, is the Lord God Almighty, who was, and is, and is to come!"