There is a Sufi story about a man who is so good that the angels ask God to give him the gift of miracles. God wisely tells them to ask him if that is what he would wish.
So the angels visit this good man and offer him first the gift of healing by hands, then the gift of conversion of souls, and lastly the gift of virtue. He refuses them all. They insist that he choose a gift or they will choose one for him. “Very well,” he replies. “I ask that I may do a great deal of good without ever knowing it.” The story ends this way:
The angels were perplexed. They took counsel and resolved upon the following plan: Every time the saint’s shadow fell behind him it would have the power to cure disease, soothe pain, and comfort sorrow. As he walked, behind him the shadow made arid paths green, caused withered plants to bloom, gave clear water to dried up brooks, fresh color to pale children, and joy to unhappy men and women. The saint simply went about his daily life diffusing virtue as the stars diffuse light and the flowers scent, without ever being aware of it. The people respecting his humility followed him silently, never speaking to him about his miracles. Soon they even forgot his name and called him “the Holy Shadow.”
– Rachel Naomi Remen in Kitchen Table Wisdom: Stories That Heal