The Prophet ﷺ said, "When a fly lands in the drink of one of you, let him dip it completely under, then throw it out, for one of its wings carries a cure and the other carries a disease."
حدثنا سليمان حدثنا إسماعيل أخبرنا عتبة بن مسلم مولى بني تميم عن عبيد بن حنين مولى بني زريق
أن النبي ﷺ قال إذا وقع الذباب في شراب أحدكم فليغمسه كله ثم ليطرحه فإن في أحد جناحيه شفاء وفي الآخر داء
Its isnad is sahih, sahih, it has already appeared at 7141. It is also found in Bukhari 6/558 no. 3535, Fath, in the Book of Virtues, the Seal of the Prophets, and in Muslim 4/1791 no. 2286, in the Book of Virtues, mentioning that he ﷺ is the Seal of the Prophets.