Institutio generalis Missalis Romani

Next the priest invites the people to pray. All, together with the priest, observe a brief silence so that they may be conscious of the fact that they are in God’s presence and may formulate their petitions mentally. Then the priest says the prayer which is customarily known as the collect and through which the character of the celebration is expressed. In accordance with the ancient tradition of the Church, the collect prayer is usually addressed to God the Father, through Christ, in the Holy Spirit,^{57Cf. Tertullian, Adversus Marcionem, IV, 9: Corpus Christianorum, Series latina, Turnhout, Belgium, 1953- (hereafter, CCSL), 1, p. 560. PL 2, 376A; Origen, Disputatio cum Heracleida, no. 4, 24: Sources chrétiennes, H. deLubac et al., editors. (Paris, 1941-), p. 62; Statuta Concilii Hipponensis Breviata, 21: CCSL 149, p. 39.} and is concluded with a trinitarian ending, that is to say the longer ending, in the following manner: If the prayer is directed to the Father: Per Dominum nostrum Iesum Christum Filium tuum, qui tecum vivit et regnat in unitate Spiritus Sancti, Deus, per omnia saecula saeculorum (Through our Lord, Jesus Christ, your Son, who lives and reigns with you and the Holy Spirit, one God, forever and ever); If it is directed to the Father, but the Son is mentioned at the end: Qui tecum vivit et regnat in unitate Spiritus Sancti, Deus, per omnia saecula saeculorum (Who lives and reigns with you and the Holy spirit, one God, forever and ever); If it is directed to the Son: Qui vivis et regnas cum Deo Patre in unitate Spiritus Sancti, Deus, per omnia saecula saeculorum (You live and reign with God the Father in the unity of the Holy Spirit, one God, forever and ever). The people, uniting themselves to this entreaty, make the prayer their own with the acclamation, Amen. There is always only one collect used in a Mass.