Musannaf Ibn Abi Shayba 33:653

Abu Usama narrated to us, from al-A’mash, from Muslim, from Masruq, who said: A righteous man went out with a pouch of dirhams in the darkness of the night, intending to give it as charity. He met a man of great wealth and gave it to him. When morning came, the people said, "Do you not wonder at so-and-so, with all his wealth? A man came to him with a pouch of dirhams and gave it to him." This reached the righteous man, and it distressed him. He said, "I do not think it was accepted from me, since I gave it to this wealthy man." He said: He went out another night with a pouch and gave it to a prostitute. When morning came, the people said, "Do you not wonder at so-and-so? A man came to her with a pouch and gave it to her, even though she does not refuse herself to anyone." This reached him, and it distressed him. He said, "I do not think it was accepted from me." He said: Then he was visited in a dream and it was said to him, "It has been accepted from you. As for what you gave to the wealthy man, we wanted to show him that there are people among the people who give charity, so that he might desire to do the same. As for the woman, she was prostituting herself out of need, so we wanted to cause her to abstain."