Sayyidah Umm Hani (may Allah be pleased with her) narrates: On the day of the Conquest of Makkah, Sayyidah Fatimah (may Allah be pleased with her) came and sat on the left of the Messenger of Allah (peace and blessings be upon him), and Sayyidah Umm Hani (may Allah be pleased with her) on his (peace and blessings be upon him) right. A girl brought a vessel with a drink in it and handed it to him (peace and blessings be upon him). He (peace and blessings be upon him) drank from it and gave it to Sayyidah Umm Hani (may Allah be pleased with her), who drank from it and said: O Messenger of Allah, I was fasting, and I have broken my fast. He (peace and blessings be upon him) said to her: "Are you making up a fast?" She said: No. He (peace and blessings be upon him) said: "Then there is no harm to you, if it was voluntary."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8350