The Prophet ﷺ drank some milk, then called for water, rinsed his mouth, and said, "It has fat in it."
حدثنا قتيبة بن سعيد حدثنا الليث عن عقيل عن الزهري عن عبيد الله بن عبد الله
أن النبي ﷺ شرب لبنا فدعا بماء فتمضمض ثم قال إن له دسما
Bukhari transmitted it in the Book of Wudu, chapter "Should one rinse the mouth after drinking milk?", hadith 211, and Muslim in the Book of Menstruation, chapter on the abrogation of wudu due to what has been touched by fire, hadith 358, from Qutayba, with this same wording.