All being now ready for the consummation of the sacrificial act, the ascription of thanksgiving and praise called the Preface is offered, which varies with the season, but closes with the Sanctus and Benedictus, sung by the choir. The Sanctus, also called Trisagion or Thrice Holy, is the cherubic hymn heard by Isaiah in vision, as described in Is. vi. 3. The Benedictus is the shout of acclamation by the concourse who met Christ on his entry into Jerusalem. There is a poetic significance in the union of these two passages. The blessed one, who cometh in the name of the Lord, is the Lord himself, the God of Sabaoth, of whose glory heaven and earth are full. The Canon of the Mass now opens with prayers that the holy sacrifice may be accepted of God, and may redound to the benefit of those present. The act of consecration is performed by pronouncing Christ’s words of institution, and the sacred host and chalice, now become objects of the most rapt and absorbed devotion, are elevated before the kneeling worshipers, and committed to the acceptance of God with the most impressive vows and invocations. As an illustration of the nobility of thought and beauty of diction that are found in the Catholic offices, the prayer immediately following the consecration of the chalice may be quoted: “Wherefore, O Lord, we thy servants, as also thy holy people, calling to mind the blessed passion of the same Christ thy Son our Lord, his resurrection from the dead, and admirable ascension into heaven, offer unto thy most excellent Majesty of the gifts bestowed upon us a pure Host, a holy Host, an unspotted Host, the holy bread of eternal life, and chalice of everlasting salvation. “Upon which vouchsafe to look, with a propitious and serene countenance, and to accept them, as thou wert graciously pleased to accept the gifts of thy just servant Abel, and the sacrifice of our patriarch Abraham, and that which thy high priest Melchisedech offered to thee, a holy sacrifice and unspotted victim. “We most humbly beseech thee, Almighty God, command these things to be carried by the hands of thy holy angels to thy altar on high, in the sight of thy divine Majesty, that as many as shall partake of the most sacred body and blood of thy Son at this altar, may be filled with every heavenly grace and blessing.” In the midst of the series of prayers following the consecration the choir sings the Agnus Dei, a short hymn which was introduced into the Roman liturgy at a very early date. The priest then communicates, and those of the congregation who have been prepared for the exalted privilege by confession and absolution kneel at the sanctuary rail and receive from the celebrant’s hands the consecrated wafer. The Post-Communion, which is a brief prayer for protection and grace, the dismissal[53] and benediction, and the reading of the first fourteen verses of the Gospel according to St. John close the ceremony.