34 But let this holy city of Rome be the first to give the example, this city which from the earliest Christian era venerate the heavenly mother, its patroness, with a special devotion. As all know, there are many sacred edifices here, in which she is proposed for the devotion of the Roman people; but the greatest without doubt is the Liberian Basilica, in which the mosaics of Our predecessor of pious memory, Sixtus III, still glisten, an outstanding monument to the Divine maternity of the Virgin Mary, and in which the "salvation of the Roman people" ( Salus Populi Romani ) benignly smiles. Thither especially let the suppliant citizens flock, and before that most sacred image let all put forth pious prayers, imploring especially that Rome, which is the principal city of the Catholic world, may also give the lead in Faith, in piety and in sanctity. We address you, children of Rome, in the words of Our predecessor of saintly memory, Leo the Great, "For although the whole world, should flourish with all the virtues, you, however, above all other peoples, should especially excel in deeds of piety, you who are founded on the citadel of the Apostolic rock, you whom Our Lord, Jesus Christ redeemed with all and the Blessed Apostle Peter instructed above all." ( Sermon III , 14; Migne, PL, LIV, 147-148).
Source: Fulgens Corona (Vatican.va)