tersanctus

Updated: May 24, 2025

Having commemorated the passion, resurrection, and ascension of Christ, as he does also after the consecration, he calls on those present to join him in prayer, he says another prayer or prayers called the secret, because said in secret, and then recites the preface to the canon, a prayer in which he unites with the celestial spirits in praise and thanksgiving as Christ himself gave thanks at the last supper: it concludes with the Tersanctus or Trisagion "Holy, Holy, Holy etc." which, as Palmer observes, has been probably used in the Christian liturgy of the east and west since the ages of the apostles.

Charles Michael Baggs - The Ceremonies of the Holy-Week at Rome