Musnad Ahmad 1118:29

Ya'qub narrated to us, he said: My father narrated to us, from Ibn Ishaq, he said: Yazid ibn Abi Habib narrated to me, from Abu Marzuq, the freed slave of Tujib, from Hanash, from Fadalah ibn Ubayd ibn Nafidh al-Ansari, who said: The Messenger of Allah, peace and blessings of Allah be upon him, came out to us on a day he was fasting. He said: "He called for water and drank." We said to him: "By Allah, O Messenger of Allah, you were fasting this day." He said: "Yes, but I vomited."