– History of the Passionists, Volume 1, Fr. Fabiano Giorgini, C.P., p. 100-101
Coming from the direction of the papal palace, Paul would have entered the Basilica from the door at the back of the building, between the main altar and the Chapel of the Madonna, known as the Borghese Chapel. The cool stillness of the chapel had a soothing effect on him, as did the painting above the altar: the icon of Mary known as Salus Populi Romani, said to have been painted by St. Luke. Kneeling there, allowing the turmoil to leave his heart, he prayed for understanding. Slowly he realised that it was not yet time for presenting the Rule to the pope; that day would come. In the meantime, he must be faithful to the inspiration God had given him. When all doors seemed closed, the only way forward was to commit himself more fully to the work he had been given to do. Before the icon of Mary, he made a vow to promote the memory of the Passion of Jesus and to work to gather companions for this purpose.
– As A Seal Upon Your Heart, Fr. Paul Francis Spencer, C.P., p. 61
Read about the Papal Basilica of St. Mary Major here