Who taught us the Trisagion (‘Holy art Thou O God..’)?
“Holy art Thou, O God!
Holy art Thou, Almighty,
Holy art Thou, Immortal,
† Crucified for us, Have mercy on us.”
“Some say that it has been taken and introduced from Isaiah the Prophet, for he saw a marvelous vision and was made worthy of a revelation from God, and heard from the Seraphim sanctifying the Lord of glory saying: “Holy, Holy, Holy, Lord of Sabaoth” (Isaiah 6:3) and from him certainly holy men adapted it and appointed it in the Church. But others say that at the time of the Crucifixion, after Christ had given up His Spirit into the hands of the Father, the holy Seraphim came together round about the body of Christ, and sang thus hymn: “Holy art Thou, O God! Holy art Thou, Almighty, Holy art Thou, Immortal. They left out the phrase ‘who was Crucified for us…” ; very rightly did they leave out this phrase since it was not for them that He was crucified but for the whole race of men. At that time, Joseph the Councilor was present, who asked for the body of Christ from Pilate the judge and embalmed it and when he heard them (the angels) saying “Holy art Thou, O God!, Holy art Thou, Almighty, Holy art Thou, Immortal, his mind was enlightened and he added – “ who was Crucified for us, Have mercy on us” Others say it was fixed in the Church by Ignatius the fiery, the disciple of Paul the Apostle. He fixed it in the present manner of singing the service in two choirs. They say he was rapt in his mind even to heaven, and saw choirs of angels, one singing praise and the other answering to it and he heard this hymn there and fixed it in the Church. But again, it is said that by the shores of the sea, there is a bird that is ever singing this song of praise. But however this may be, it was by this holy man (Ignatius) that it was fixed in the Church.”
[Ref: (edited) Pg 13, 14; Moses Bar Kepha: Commentary on the Eucharist; Translated by Rev Fr Dr. B Varghese, 2014 edition, MOC Publications Kottayam.], article by Rincy Raju, Ahemedbad.