I heard him narrate that the Messenger of Allah ﷺ came out to them on a day he used to fast. He called for a vessel of water and drank from it.We said, "Messenger of Allah, this is a day you used to fast."He replied, "Yes, but I vomited."
حدثنا محمد بن عبيد حدثنا محمد بن إسحاق عن يزيد بن حبيب عن أبي مرزوق
سمعته يحدث أن رسول الله ﷺ خرج عليهم في يوم كان يصومه فدعا بإناء فيه ماء فشرب فقلنا يا رسول الله إن هذا اليوم كنت تصومه قال أجل ولكن قئت
Its isnad is sahih. Abu Marzuq is Habib bin Shaheed Tujaybi, and he is a trustworthy Egyptian narrator, whose hadith appears in some of the Sunan works.The hadith was narrated by Ibn Majah, 1/536, no. 1675, and Busiri said about it, there is weakness and a break in the chain, as Abu Marzuq did not hear from Fadala, though Ajli and Ibn Hibban disagreed with this assessment.The hadith was also narrated by Daraqutni, 2/182, and Bayhaqi, 4/220.