It often happened that a Brother was put in special charge of a single leper, whose companion and servant he continued to be, sometimes for a long period.[38] The following narrative shows Francis's love for these unfortunates, and his method with them.[39] It happened one time that the Brothers were serving the lepers and the sick in a hospital, near to the place where St.Francis was.

Among them was a leper who was so impatient, so cross-grained, so unendurable, that everyone believed him to be possessed by the devil, and rightly enough, for he heaped insults and blows upon those who waited upon him, and what was worse, he continually insulted and blasphemed the blessed Christ and his most holy Mother the Virgin Mary, so that there was no longer anyone who could or would wait upon him.

The Brothers would willingly have endured the insults and abuse which he lavished upon them, in order to augment the merit of their patience, but their souls could not consent to hear those which he uttered against Christ and his Mother.

They therefore resolved to abandon this leper, but not without having told the whole story exactly to St.Francis, who at that time was dwelling not far away.
When they told him St.Francis betook himself to the wicked leper; "May God give thee peace, my most dear brother," he said to him as he drew near.
"And what peace," asked the leper, "can I receive from God, who has taken away my peace and every good thing, and has made my body a mass of stinking and corruption ?" St.Francis said to him: "My brother, be patient, for God gives us diseases in this world for the salvation of our souls, and when we endure them patiently they are the fountain of great merit to us." "How can I endure patiently continual pains which torture me day and night?
And it is not only my disease that I suffer from, but the friars that you gave me to wait upon me are unendurable, and do not take care of me as they ought." Then St.Francis perceived that this leper was possessed by the spirit of evil, and he betook himself to his knees in order to pray for him.

Then returning he said to him: "My son, since you are not satisfied with the others, I will wait upon you." "That is all very well, but what can you do for me more than they ?" "I will do whatever you wish." "Very well; I wish you to wash me from head to foot, for I smell so badly that I disgust myself." Then St.Francis made haste to heat some water with many sweet-smelling herbs; next he took off the leper's clothes and began to bathe him, while a Brother poured out the water.