Pope Francis employed a colloquial hand gesture as he preached forgiveness Thursday during a pilgrimage to his namesake’s hometown.

The pope acknowledged the difficulty of granting forgiveness during remarks inside the St. Maria of Angels Basilica, saying off the cuff, “It is difficult to forgive. How much it costs us to forgive the others. Let’s think about it.”

He likened forgiveness to a caress. And he made a hand gesture to illustrate the point, saying, “It is far from the gesture, ‘You will pay,'” as he flicked his thumb against his upper teeth. “Forgiveness is something else.”

The pope made the brief visit to Assisi to pray at tiny church within the basilica, which is called the Portiuncula and considered the cradle of the Franciscan order. It is there, according to tradition, that St. Francis in 1216 received a vision that led Pope Honorius to grant forgiveness to pilgrims visiting the Portiuncula to confess their sins.

Throngs of well-wishers greeted the pope as he made his way through the basilica, grabbing his vestments and kissing his hand even as he had his attention elsewhere. Francis stopped several times to offer his blessings to children and babies, caressing or kissing their heads.

Before returning to the Vatican, the pope spent about an hour hearing the confessions of 19 people, including a Franciscan friar, two priests and four scouts.

Francis also shook hands with Perugia’s imam in a receiving line outside of the Basilica alongside local bishops and Franciscan friars. The religious leader was among dozens of imams who went to church in France and Italy on Sunday to show their solidarity after the murder of a French priest in France’s Rouen cathedral.