Musnad Abu Ya'la al-Mawsili 163:12

'Isa ibn Salim narrated to us, Wahb ibn 'Abd al-Rahman al-Qurashi narrated to us, from Ja'far ibn Muhammad, from his father, from al-Hasan ibn 'Ali, that he entered the place of ablution and found a morsel—or he said: a piece of bread—in the path of excrement and urine. He took it, removed the filth from it, and washed it thoroughly. Then he gave it to his servant and said, "O servant, remind me of it when I have performed ablution." When he had performed ablution, he said to the servant, "O servant, hand me the morsel—or he said: the piece of bread." The servant said, "O my master, I have eaten it." He said, "Then go, for you are free for the sake of Allah." The servant said to him, "O my master, for what reason did you free me?" He said, "Because I heard from Fatimah, daughter of the Messenger of Allah, mentioning from her father, the Messenger of Allah (may Allah bless him and grant him peace): 'Whoever finds a morsel or a piece of bread in the path of excrement and urine, takes it, removes the filth from it, washes it thoroughly, and then eats it, it will not settle in his stomach until he is forgiven.' And I would not have a man from the people of Paradise serve me."