they stand, the cantor before them, and he recites in Hebrew—words whose sense is as follows, and which they do not repudiate: “We sanctify You, we magnify You, and we offer You a threefold sanctification, just as it is written on the tongue of Your Prophet.”
The whole congregation then cries out in response: “Holy, Holy, Holy, Lord of hosts, Lord of the heavens and the earth!”
How clear, then, is their acknowledgment of the Trinity, and how grave their unbelief in what it truly implies. For we, because of this explicit statement that God delivered in the Torah and in the Books of the Prophets—and they have made it into three hypostases, one essence, one nature, one God, one Lord, and one Creator—this is what we say: Father, Son, and Holy Spirit.

The reply: Whatever is found in the Books of the Prophets (peace be upon them) of repeating the Lord’s name when it is linked to another created being belongs to the same rhetorical pattern as the repetition of the name “God.”