Musnad Ahmad 1166:11

Aswad ibn Amir narrated to us, he said: Isra'il narrated to us, from Simak, from a man, from Umm Hani, who said: When it was the day of the conquest of Mecca, Fatimah came and sat to his left, and Umm Hani came and sat to his right. A servant girl came with a drink, and the Prophet, peace and blessings of Allah be upon him, took it and drank. Then he handed it to Umm Hani on his right. She said: "I was fasting." He said to her: "Is it something you are making up?" She said: "No." He said: "Then it does not harm you."