Terce is a fixed time of prayer of the Divine Office of the almost all the Christian liturgies. It is consists mainly of psalms and is said at 9 a.m. Its name comes from Latin and refers to the third hour of the day after dawn.
Adapted from the Catholic Encyclopedia of 1917; note that this describes the office before the reforms of the Second Vatican Council; the Psalm numbers given are first for the Septuagint and Vulgate and then for the Hebrew and English systems.:
Clement and Tertullian in these passages refer only to private prayer at these three hours. The Canons of Hippolytus also speak of these three hours as suitable for private prayer. However, on the days called "days of station", that is to say Wednesday and Friday, which were set apart as especially consecrated to prayer, and Sunday, these hours were recited in public (Canon, xx, xxvi). St. Cyprian remarked that these three hours had been observed in the Old Testament, and that Christians should also observe them (De Oratione, XXXIV). In the fourth century the custom of praying at these hours became more frequent, and even obligatory, at least for monks (see the texts of the Apostolic Constitutions, of St. Ephrem, of St. Basil, of the author of "De Virginitate" quoted in Bäumer-Biron, "Histoire du bréviaire", 116, 121, 129, 186). Our texts say nothing as to what were the elements of the prayer of Terce, Sext, or None before the fourth century. Doubtless, like all prayers at that time, they were composed of psalms, canticles, hymns, and litanies. It is from the fourth century onwards that we can gather a more precise idea as to the composition of the hour of Terce. In the fourth century, as we have said, the custom of prayer at Terce spread, and tended to become obligatory, at least for monks. There is no mention in the "Peregrinatio ad Loca Sancta" of an office of Terce on ordinary days. Some authors have misunderstood the text here, but there is no mention of a meeting at this hour, except on Sunday and during Lent. The hour of Terce is also mentioned in St. Jerome, "Ep. ad Lætam."; "Ep. ad Eustoch."; in the Life of St. Melania the Younger, "Analecta Bollandiana", VIII; in Cassian, "De institut. coenob.", etc.
At this period it is composed of the same elements as the hours of Sext and None; the distribution is the same, and it is clear that the three "little hours" were composed at the same time and that they have the same origin. The psalms of Terce are different from those of the other two hours. There were also certain varieties of composition. Thus, in certain countries, three psalms were assigned to Terce, six to Sext, nine to None, in virtue of the symbolism.
On Sundays and Mondays the Gradual Psalms are replaced by three octonaries (i.e. three sections of eight verses each) of Psalm 118 (119). In the Mozarabic Rite, three octonaries of Ps. 118 (119) are also recited, the composition otherwise differing very little. In the main, the recitation of three psalms at Terce, as at the other two "little hours" of the day, is founded on a universal and very ancient tradition. Divergencies on this point are only exceptional. The practice of the Roman Liturgy, which at first sight appears to be somewhat different, may be traced to this tradition also. In this rite a part of Ps. 118 (119) is recited at Terce as well as at the other "little hours", the psalm being divided into three double octonaries. In the Psalter arrangement of 1911-12, the psalms are: on Sunday, Ps. 118 (119) (three divisions); on Monday, Ps. 26 (27) (two divisions); on Tuesday, Ps. 39 (40) (three divisions); on Wednesday, Ps. 53 (54) (two divisions); on Thursday, Ps. 72 (73) (three divisions); on Friday, Ps. 39 (40) (two divisions); on Saturday, Ps. 101 (102) (three divisions). The number three is therefore preserved in each case.
The hymn "Nunc Sancte nobis Spiritus" recalls the descent of the Holy Ghost upon the Apostles. The other elements are the same as for Sext and None.
Terz (Gebet) | Terts (getijde) | Ceasul al treilea canonic | Tice