The rest of his birthday was spent sharing breakfast with homeless people before celebrating Mass as greetings flowed in from around the world.
They were invited from among those staying around St. Peter's Square and at nearby showers for the homeless established by the pope's almsgiver.
The Pope told the audience of 60 cardinals: 'For some days now, I have had in mind a word that seems ugly: Old age, a thought that frightens'.
LaSpada said that besides praying the joyful mysteries of the rosary on the pope's birthday, rosary ambassadors should ask a friend to do the same "thus multiplying our spiritual gift to the Holy Father" and should promise "to live each day in the light of God's love through love of neighbor".
"This spiritual bouquet represents the good wishes and blessings sent by millions throughout the world who will be praying the rosary on the Holy Father's birthday to thank God for the gift of Pope Francis".
But then he recalled his words during his first papal greeting in 2013, when he said: 'Old age is the thirst for knowledge.
To the cardinals he added: "I hope it will be the same for me".
Greetings arrived from all corners of the globe in the form of both personal messages and succinct tweets with the hashtag #Pontifex80.
Nigeria's president, Muhammadu Buhari has congratulated the head of the the Roman Catholic Church Pope Francis as he turns 80 on Saturday, December 17.