Pope Paul VI
Sacerdotalis Caelibatus §99
Sacerdotalis Caelibatus: On the Celibacy of the Priest
99 The Church proclaims her hope in Christ; she is conscious of the critical shortage of priests when compared with the spiritual necessities of the world's population; but she is confident in her expectation which is founded on the infinite and mysterious power of grace, that the high spiritual quality of her ministers will bring about an increase also in their numbers, for everything is possible to God. (l52) In this faith and in this hope, may the apostolic blessing which we impart with all Our heart be for all a pledge of heavenly graces and the testimony of Our fatherly affection. Given at Rome, at St. Peter's, June 24, 1967, the feast of St. John the Baptist, in the fifth year of Our pontificate.
Source: Sacerdotalis Caelibatus (Vatican.va)