We encountered Abba John the Persian at the Lavra of Monidia and he told us this about Gregory the Great, the most blessed Bishop of Rome:
“I went to Rome to pray at the tombs of the most blessed Apostles, Peter and Paul. One day as I was standing in the city-centre I saw that Pope Gregory was going to pass by. I had it in mind to prostrate myself before him. The attendants of the pope began saying to me, one by one, ‘Abba, do not prostrate yourself’, but I could not understand why they had said that to me; certainly it seemed improper for me not to prostrate myself. When the pope came near and perceived that I was about to prostrate myself – the Lord is my witness brethren – he prostrated himself down to the ground and refused to rise until I had got up. He embraced me with great humility, handed me three pieces of gold and ordered me to be given a monastic cloak, stipulating that all my needs were to be taken care of. So I glorified God Who had given him such humility towards everybody, such generosity with alms and such love.”
St. John Moschos
The Spiritual Meadow, p. 124.