The text is from Isaiah 35:4: "Take courage, you who are fainthearted, and do not fear; behold, our God will come and he will save us." Here's the score:
Here again are links to all the Introits for Advent; this Sunday is Gaudete in Domino, "Rejoice!":
- Advent 1: Ad Te Levavi Animam Meam
- Advent 2: Populus Sion
- Advent 3: Gaudete in Domino
- Advent 4: Rorate cæli desuper
And this Sunday itself is called Gaudete, too; the color is rose ("Rejoice!"), and the pink candle on the Advent wreath is lit.
The collect for this week is the famous "stir up" one:
Stir up your power, O Lord, and with great might come among us; and, because we are sorely hindered by our sins, let your bountiful grace and mercy speedily help and deliver us; through Jesus Christ our Lord, to whom, with you and the Holy Spirit, be honor and glory, now and for ever. Amen.
The following is from Commentary on the American Prayer Book, by Marion Hatchett:
The Gelasian sacramentary is the source for this collect which is included in the first of the propers for Advent (no. 1121), and is addressed to the Son. In the Gregorian it is changed to a prayer addressed to the Father in a proper for a Sunday, included after the provisions for a winter ember vigil (no. 805). The Gallican Bobbio missal provides it as a second prayer in the first of the three Masses for Advent (no. 38). In the Sarum missal it was appointed for the fourth Sunday in Advent. Cranmer retained it in that version with slight changes, adding the phrase "among us" and, at the end of the petition, "through the satisfaction of thy Son our Lord." Revisers in 1662 added the phrase "in running the race that is set before us," and expanded "deliver us" to "help and deliver us." Cranmer's second phrase was deleted in the 1928 revision and the first of the additions of the 1662 edition has been dropped in the present revision, thus restoring the prayer to a form close to its original. The prayer echoes Psalm 80:2 and Hebrews 12:1. The one remnant of a series of four prayers which began with "excita" (stir up) used on four of the last five Sundays before Christmas in the Sarum missal, this prayer sets forth better than the others the themes of the two advents: the first in which He came in humility, and the second in which He comes in power; the first in which He came to save, and the second in which He comes to help and relieve.
The rubric following is a reminder that the Wednesday, Friday, and Saturday of this week are the traditional winter ember days, though these may now be transferred to a time related to local or diocesan occasions for ordination.