سنن أبي داود

Narrated Umm Hani:

On the days of the conquest of Mecca, when Mecca was captured, Fatimah came and sat on the left side of the Messenger of Allah (ﷺ), and Umm Hani was on his right side. A slave-girl brought a vessel which contained some drink; she gave it to him and he drank of it. He then gave it to Umm Hani who drank of it. She said: Messenger of Allah, I have broken my fast; I was fasting. He said to her: Were you making atonement for something? She replied: No. He said: Then it does not harm you if it was voluntary (fast).