The Messenger of Allah ﷺ said, "Perform ablution after eating what fire has touched."
قال رسول الله ﷺ: توضؤوا مما مست النار.
No references are available.
Muslim narrated it in the Book of Menstruation (353), from the hadith of Ibn Shihab, "Saeed bin Khalid told me that he asked Urwa bin Zubayr about wudu after eating something touched by fire." Urwa said, "I heard Ayesha," and he related the hadith.