29 It should be noted, however, that this full obedience of his to the commands of his superiors rested on supernatural principles; in acknowledging and duly obeying ecclesiastical authority, he was paying the homage of faith to the words of Christ the Lord as He told His Apostles "He who hears you, hears me." (43) To conform himself faithfully to the will of his superiors he habitually restrained his own will, whether in accepting the holy burdens of hearing Confessions, or in performing zealously for his colleagues in the apostolate such work as would produce richer and more saving fruits.
Source: Sacerdotii Nostri Primordia (Vatican.va)