Isaiah’s vision of the Lord enthroned in the temple includes creatures he calls seraphim. Each has six wings: two covering the face, two covering the feet, and two for flying. They cry to one another, “Holy, holy, holy is the Lord of hosts.” The name itself is related to a Hebrew root meaning “to burn,” so they are often understood as the burning ones.

In later Christian angelology the seraphim occupy the highest rank of the nine choirs of angels. Closest to God, they are consumed with love and pure adoration. Medieval writers and artists developed the imagery—flames, multiple wings, faces of intense focus. The Trisagion, the thrice-holy hymn, entered the liturgy of both East and West as an echo of their cry.

Jewish tradition also retains the seraphim, sometimes identifying them with the fiery serpents of the wilderness or with other heavenly beings. Across the traditions they remain remote from ordinary experience, yet their function is clear: they model the ceaseless worship that is the proper response to the divine presence.

When the church sings “Holy, holy, holy,” it joins, at least in intention, the song that the seraphim never stop singing.