The Prophet ﷺ said, "Rinse your mouths after drinking milk, for it has fattiness to it."
حدثنا عبد الرحمن بن إبراهيم الدمشقي حدثنا الوليد بن مسلم حدثنا الأوزاعي عن الزهري عن عبيد الله بن عبد الله بن عتبة
أن النبي ﷺ قال مضمضوا من اللبن فإن له دسما
Bukhari narrated it in the chapters on Drinks, in the chapter "Drinking Milk, and the Saying of Allah, Mighty and Sublime, 'From Between Excretion and Blood,'" hadith 5609, from the hadith of Uzai, and Muslim narrated it in the chapters on Menstruation, in the chapter "The Abrogation of Wudu Being Required for What Fire Has Touched," hadith 358, from the hadith of Zuhri, with a different wording than this.