Sayyidah Umm Ayman (may Allah be pleased with her) narrates: The Prophet (peace and blessings be upon him) got up at night, went to a vessel in a corner of the house, and urinated in it. I got up at night feeling thirsty and drank what was in that vessel without knowing. In the morning the Prophet (peace and blessings be upon him) said: "O Umm Ayman, get up and pour out what is in that vessel." I said: "By Allah, I have drunk what was in it." Sayyidah Umm Ayman (may Allah be pleased with her) says: The Prophet (peace and blessings be upon him) laughed until his back teeth became visible. Then he said: "Now you will never have pain in your stomach."
Al-Tabarani recorded it; its chain contains Abu Malik al-Nakha'i, who is da'if (weak).