The Pope made the gesture and accompanying remarks while flying from Sri Lanka to the Philippines, where he started a five-day visit Thursday
He didn't mention Charlie Hebdo, the satirical magazine that was targeted by terrorists after it depicted the Prophet Mohammed in cartoons, something that many Muslims find offensive. The Paris magazine became a terrorist target after publishing one such cartoon years ago, and after last week's attack, it placed Mohammed on its cover, this time showing him crying and holding a sign with the rallying cry "Je suis Charlie," French for "I am Charlie."
Still, even if he didn't explicitly name the publication, the Pope was clear that he was referring to the general debate over what's happened in France, including how people might react if they feel someone made a slight to their religious faith.
Everyone has not only the liberty, but also the obligation, "to say what he thinks to help the common good," Francis said. However, they should not do so if it offends people.
And if someone does get offended? The Pope made reference to Alberto Gasbarri, a man who organizes papal trips and was then standing next to him on the plane.
"If Dr. Gasbarri, a great friend, says a swear word against my mother, then a punch awaits him," Francis said. "It's normal, it's normal. One cannot provoke, one cannot insult other people's faith, one cannot make fun of faith."
While making this comment, Vatican Radio reported that the pontiff "gestured with a pretend punch" directed at Gasbarri -- an action many journalists interpreted as a joke.
Notably, in the same conversation, Francis steadfastly denounced the terrorists' killings and the idea that anyone -- as the France attackers apparently did -- could pretend to justify such violence in the name of God.
"One cannot make war (or) kill in the name of one's own religion," Francis said on his way to the Philippines. "... To kill in the name of God is an aberration."
The Vatican later responded to a CNN question about the "punch" remark specifically.
In an email, Vatican spokesman Thomas Rosica told CNN that "the Pope's expression is in no way intended to be interpreted" as somehow justifying last week's violence, and he pointed out that "the Pope has spoken out clearly against the terror and violence that occurred in Paris and in other parts of the world."
"The Pope's words about Dr. Gasbarri were spoken colloquially and in (a) friendly, intimate manner among colleagues and friends," Rosica said Thursday. "His response might be similar to something each of us has felt when those dearest to us are insulted or harmed."
Rosica explained Francis' remarks as consistent with his "free style of speech," a plainspoken and conversational approach that has earned him admirers. Such remarks "must be taken at face value and not distorted or manipulated," the Vatican spokesman said.
In fact, the Pope has been one of the world's most outspoken advocates for peace and against war since taking that position in 2013.
And what he said on the Manila-bound plane doesn't change that, according to Rosica.
"Pope Francis has not advocated violence with his words on the flight," the spokesman said.