Abu Marzuq says: I heard Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) narrate that the Messenger of Allah (peace and blessings be upon him) came out to them on a day on which he used to fast. He called for a vessel of water and drank, so we said: "O Messenger of Allah, you used to fast on this day?" He (peace and blessings be upon him) said: "Yes, but I vomited."
Hadith Referenceالمعجم الكبير للطبراني / باب الفاء / 15909