1537. "The word order in Roman antiquity designated an established civil body, especially a governing body. Ordinatio means incorporation into an ordo. In the Church there are established bodies which Tradition, not without a basis in Sacred Scripture,[Cf. Heb 5:6 ; Heb 7:11 ; Ps 110:4 .] has since ancient times called taxeis (Greek) or ordines. And so the liturgy speaks of the ordo episcoporum, the ordo presbyterorum, the ordo diaconorum. Other groups also receive this name of ordo: catechumens, virgins, spouses, widows,.... "

1538. "Integration into one of these bodies in the Church was accomplished by a rite called ordinatio, a religious and liturgical act which was a consecration, a blessing or a sacrament. Today the word 'ordination' is reserved for the sacramental act which integrates a man into the order of bishops, presbyters, or deacons, and goes beyond a simple election, designation, delegation, or institution by the community, for it confers a gift of the Holy Spirit that permits the exercise of a 'sacred power' (sacra potestas)[Cf. LG 10.] which can come only from Christ himself through his Church. Ordination is also called consecratio, for it is a setting apart and an investiture by Christ himself for his Church. The laying on of hands by the bishop, with the consecratory prayer, constitutes the visible sign of this ordination."

1541. "The liturgy of the Church, however, sees in the priesthood of Aaron and the service of the Levites, as in the institution of the seventy elders,[Cf.Num 11:24-25] a prefiguring of the ordained ministry of the New Covenant. Thus in the Latin Rite the Church prays in the consecratory preface of the ordination of bishops:

God the Father of our Lord Jesus Christ.. . by your gracious word you have established the plan of your Church. From the beginning, you chose the descendants of Abraham to be your holy nation. You established rulers and priests and did not leave your sanctuary without ministers to serve you....[Roman Pontifical, Ordination of Bishops 26, Prayer of Consecration.] "

1542. "At the ordination of priests, the Church prays:

Lord, holy Father, . . . when you had appointed high priests to rule your people, you chose other men next to them in rank and dignity to be with them and to help them in their task.... you extended the spirit of Moses to seventy wise men.... You shared among the sons of Aaron the fullness of their father's power.[Roman Pontifical, Ordination of Priests 22, Prayer of Consecration.] "

1543. "In the consecratory prayer for ordination of deacons, the Church confesses:

Almighty God . . .. You make the Church, Christ's body, grow to its full stature as a new and greater temple. You enrich it with every kind of grace and perfect it with a diversity of members to serve the whole body in a wonderful pattern of unity. You established a threefold ministry of worship and service, for the glory of your name. As ministers of your tabernacle you chose the sons of Levi and gave them your blessing as their everlasting inheritance.[Roman Pontifical, Ordination of Deacons 21, Prayer of Consecration.] "