Introit

(a.) (Officium Saruns, 'ταοΕοχ, Eastern; Ingressa, Ambrosian) is the name (from the Latin ihtroire, to enter) of a psalm or hymn, but now properly the former, sung in some churches as the priest goes up to the altar to celebrate the Eucharist. "Introitum autem vocamus antiphonam illam quam chorus cantat et sacerdos ut ascendit ad altare legit cum versu et gloria" (Martene, De Antiq. Monach. Rit; II, 4:9). According to Symeon of Thessalonica, the introit typifies the union of men and angels. According to Freeman (Princ. of Divine Service, 2, 316), the true introit consists of the "Hymn of the only-begotten Son" in the East. and the Gloria in Excelsis in the further East and the whole Western Church. Neale too remarks (Introd. to the East. Ch. p. 363) that the "introits of the liturgies of St. Mark, and St. James, and the Armenian consist of the hymn 'Only begotten Son.'" But, besides the Introit proper, there are general in the Western Church a psalm or hymn, with antiphon, varying according to the season; and in the liturgy of Chrysostom we find no less than three of these. Walcott (Sac. Archaeol. p. 331) says the introit is of two kinds:

(1.) regular, that sung daily;

(2.) the irregular, which is chanted on festivals. The latter be describes as having been of old of a grand and solemn character. "In a great church there was a procession round the nave to the sound of bells and with incense, passing out by the small gate of the sanctuary and reentering by the great doors. The deacon then went up with the Gospel elevated in both his hands, and set it on the midst of the altar, so as to be seen by the people. Then followed the introit, composed of several anthems, succeeded by prayers and the Trisagion. The priest and deacon intoned it, the choir and people took it up, and a candlestick with three lights, as a symbol of the Holy Trinity, was lighted." The introit is believed to have originated with pope Celestine (A.D. 422-432), c. 430 (comp. Bona, 3:48). Before that time the mass had immediately succeeded the Epistles of Paul and the Gospel. "Its structure is that of an antiphon, followed generally by a whole psalm or a portion of a psalm (compare, however, Neale, Essays on Liturgy, p. 138 sq.), and the Gloria Patri, and then by a repetition of the whole or part of the commencing antiphon. In the old Gregorian introit the antiphon was repeated three times, a custom found also in the Sarum rite; this triple recitation being connected mystically with the three laws viz., the Natural, the Mosaic, and the Evangelic." In the English Church the introit was introduced by Edward VI, in his Prayer-book, before every collect, epistle, and gospel. It is a psalm containing something proper for the particular Sunday or holiday to which they were applied; but they were afterwards struck out, and the choice of the psalm was left to the clergyman. The introits of each Sunday and holiday are given by Wheatley in his Common Prayer, p. 205. See Blunt, Theol. Cyclop. 1, 355 sq.; Eadie, Eccles. Dict. s.v.; Augusti, Flandbuch d. Christl. Archaöl. 2, 773; Siegel, Archaöl. 3, 378. See also Mass.

(b.) This word also designates the verses sung at the entering of the congregation into the church, a custom as old as the 4th century, called ingressa in the Ambrosian Ritual. See Palmer, Origines Lit. 2, 19.