According to Franciscan scholars, the unbulled rule, officially approved by the Order in the General Chapter of 1221, went back to before Anthony's entrance in the Minorite family.

It is, therefore, probable that the monks read him their forma vitae, including Chapter 16 which says, "Any monk who wishes to go among the Saracens and other infidels goes with the permission of his minister and servant."

The minister then should give him his permission and should not create obstacles if he sees that the monk is fit to be sent." And it is known that Anthony immediately "took advantage" of this in his passage to the new order. Anthony, like Francis, was a missionary among the Saracens, but for him, too, the Lord planned another field of work: being a missionary-preacher in the Christian lands, especially in those places where heresy nested. How did Anthony begin to take on this role? He thought back on his experience: the impossibility of his dream of martyrdom, his reviewing of his identity as a Franciscan follower, taking a look at it within a project not yet completely clear, waiting for a sign. This sign came in the Assembly of Forlì, in September of 1222, when, even though he was not trained to be an itinerant preacher, he is forced by obedience - a gesture that more commonly characterised the monastic-canonical life than the vitality of the pauperistic Franciscan movement - to take the path of predication of the Gospel.

Zeal burned in the heart of Anthony. He never rested in his itinerant predication. His days were not long enough to hear all the confessions of the penitents. As is attested by biographical sources and as has been seen in the recent recognition of the Saint's body, "Anthony died of extreme weakness from excessive work due to meagre and inadequate nutrition and lack of rest." (V. Gamboso).

Francis "usually divided and designated his time between doing good for his fellow man and solitary contemplation" and "He praised those preachers who took care of themselves every once in a while and nourishes himself on knowledge" (Celano). Like the seraphic Father, Anthony, too, alternated his apostolic duties with long periods of silence and contemplative prayer. After the silence of Montepaolo, he went on the to retreat in the hermitage of Brive in France, and to Camposampiero (to cite the places where the memory of the Saint has lingered on); days of predication where followed by nights passed in prayer.

Francis pointed out to the monks, in the letter to the Chapter, that the Lord "sent them for the whole world, so that they would give testimony to his voice in words and deeds." Anthony felt invested with this mission and announced with words and with his life that "he who in his deeds destroys the Lord's doctrine pointlessly brags of knowing the Scripture" and that "we can speak to others of humility, poverty, of patience and obedience when we show their presence in ourselves."

Anthony received the ideals of poverty and of being a missionary from the Franciscans, but he innately shared some other values of Francis'. He underlines two in particular: the spirit of prayer and the love of the Church.