Vatican spokesman Alessandro Gisotti said that Francis was concerned about hygiene when, after greeting throngs of well-wishers in a lengthy receiving queue in Loreto on Monday, he began pulling his hand away to discourage people from kissing his ring and spreading germs to others.
Video of the incident went viral, with conservative critics blasting what they said was Francis' disrespect for the tradition.
Mr Gisotti said it was nothing of the sort.
He noted that Francis is more than happy to receive the greeting in small groups, as he did on Wednesday when plenty of people kissed his ring during his general audience.
Mr Gisotti said he had just spoken to the pope about it.
"The Holy Father told me that the motivation was very simple: hygiene," Mr Gisotti told reporters.
"He wants to avoid the risk of contagion for the people, not for him."
The tradition of kissing the ring of a bishop or pope goes back centuries, as a sign of respect and obedience.
"You all know that he has a great joy in meeting and embracing people, and being embraced by them," Mr Gisotti said.
Francis is known for gleefully embracing babies given to him to kiss and, germs be damned, sipping from mate gourds offered to him by strangers when he is out and about on his popemobile.
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