Sayyidah Umm Hani (may Allah be pleased with her) said: I was sitting with the Prophet (peace and blessings be upon him) when a drink was brought to him (peace and blessings be upon him). He (peace and blessings be upon him) drank from it, then handed it to me, and I also drank from it. I said: O Messenger of Allah! I have committed a sin, so seek forgiveness for me. He (peace and blessings be upon him) said: "What is that?" I said: I was fasting, and I broke my fast. The Messenger of Allah (peace and blessings be upon him) said: "Was it a make-up fast that you were making up?" I said: No. He (peace and blessings be upon him) said: "Then it does you no harm."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21359