This Eucharistic Miracle was performed directly by Saint Anthony after he was challenged by a certain Bonovillo to demonstrate the truth of the Real Presence of Jesus in the Eucharist. The most ancient biography of Saint Anthony, L'Assidua (The Untiring), carries Bonovillo's exact words: "Father!
I tell you before all these people: I will believe in the Eucharist if my mule, after fasting for three days, eats the Host which you offer him rather than the fodder which I give him." The mule, despite the fact that it was exhausted by hunger, knelt before the Host and refused its food.
In Rimini, it is still possible today to visit the church that was built in honor of the Eucharistic miracle performed by Saint Anthony of Padua in 1227. This episode is cited in "Beginnitias," considered one of the most ancient sources regarding the life of Saint Anthony.
"This saintly man was speaking with a faithless heretic who opposed to the sacraments of the Eucharist and whom the saint had nearly led to the Catholic faith.
But, after numerous arguments, the heretic declared: 'If you, Anthony, produce a miracle and demonstrate to me that the Body of Christ is truly in Communion, I will completely renounce my heresy and immediately convert to the Catholic faith. Why don't we have a wager?
I'll keep one of my beasts locked up for three days to feel the torments of hunger. Then I will bring it forth in public and show it food. You will stand in front of it with what you maintain is the Body of Christ.
If the beast, leaving aside its food, hurries to adore its God, I will share the faith of you Church.'" Saint Anthony, illuminated and inspired from above, accepted the challenge.
the priest and heretic entered the Grand Piazza (today the Three Martyrs Piazza). Saint Anthony was followed by Catholic faithful; Bonovillo (this was the name of the Charisian by his allies in unbelief. The saint held between his hands the consecrated Host, contained in a monstrance; the heretic held his hungry mule.
The saint, after having requested and obtained silence, turned to the mule with these words: "In virtue and in the name of your Creator, who I, as unworthy as I am, hold in my hands, I tell and order you: Come forward immediately and render homage to the Lord with all the respect so that heretics and unbelievers may understand that all creatures must humble themselves before their Creator whom priests hold in their hands at the altar." And immediately the animal, refusing the food offered by its master, docilely approached the priest.
It bent its front legs before the Host and paused there in a reverently. Anthony's adversary was true to his word, and threw himself at the saint's feet denouncing publicly the errors of his ways. From that day he became one of the most zealous cooperators of the miracle-working saint.