Isaiah 6:1-3

Isaiah six, verses one through three, opens the prophet's own account of his commissioning with a vision set in the year King Uzziah died. Isaiah reports seeing the Lord seated on a high and lofty throne, the train of his robe filling the temple, attended by seraphim, six winged beings who cover their faces with two wings, their feet with two more, and fly with the remaining two. The seraphim call to one another in words that became one of scripture's most repeated liturgical formulas, holy, holy, holy is the Lord of hosts, the whole earth is full of his glory, a threefold repetition read since antiquity as an intensifying superlative rather than as three separate claims. The vision is set specifically within the temple, giving Isaiah's commissioning a concrete architectural and cultic setting rather than a placeless or purely inward experience, and the passage's opening date, tied to a named king's death, anchors the vision to a specific moment in Judah's political history rather than leaving it undated, a detail scholars have used to place the call narrative within the prophet's own lifetime rather than treating it as a timeless or purely symbolic scene detached from any historical setting.

The seraphim's threefold acclamation in Isaiah six outgrew its original setting almost immediately within later religious history. Jewish liturgy incorporated the words into the Kedushah, recited during the repetition of the Amidah prayer, treating the congregation's own recitation as a participation in the same praise the seraphim offer around the throne. Christian liturgy took up the same threefold formula independently as the Sanctus, sung or recited within the eucharistic prayer in traditions ranging from Roman Catholic to Eastern Orthodox to many Protestant churches, and the Greek Orthodox Trisagion, thrice holy, draws its name directly from this same triple repetition, though scholars distinguish the Trisagion as a related but separately developed liturgical text rather than a simple quotation. The seraphim themselves, described nowhere else in the Hebrew Bible in comparable detail, became a fixed category within later angelology largely on the strength of this one vision, illustrating how a single narrated scene can generate both an enduring visual type of being and a phrase repeated in worship across two religious traditions that otherwise read the surrounding chapters of Isaiah very differently from one another.