10 And even as at that period the blessed Father Dominic Guzman was occupied in defending the integrity of heavensent doctrine and in dissipating the perverse errors of heretics by the light of Christian wisdom, so was the grace granted to St. Francis, whom God was guiding to the execution of great works, of inciting Christians to virtue, and of bringing back to the imitation of Christ those men who had strayed both long and far. It was certainly no mere chance that brought to the ears of the youth these counsels of the gospel: "Do not possess gold, nor silver, nor money in your purses; nor scrip for your journey, nor two coats, nor shoes, nor a staff."(2) And again, "If thou wilt be perfect, go sell what thou hast, and give to the poor... and come, follow Me."(3) Considering these words as directed personally to himself, he at once deprives himself of all, changes his clothing, adopts poverty as his associate and companion during the remainder of his life, and resolves to make those great maxims of virtue, which he had embraced in a lofty and sublime frame of mind, the fundamental rules of his Order.
Source: Auspicato Concessum (Vatican.va)