I was with Marwan when Abu Saeed came in. Marwan asked, "Did you hear the Messenger of Allah ﷺ forbid blowing into a drink?"Abu Saeed replied, "Yes."A man said, "But I cannot quench my thirst in a single breath."Abu Saeed said, "Then move the cup away from your mouth and breathe."The man said, "I see a speck of dirt in it."Abu Saeed said, "Then pour it out."
حدثنا يحيى بن سعيد عن مالك حدثني أيوب بن حبيب
كنت عند مروان فدخل أبو سعيد فقال سمعت رسول الله ﷺ ينهى عن النفخ في الشراب قال نعم فقال رجل إني لا أروى من نفس واحد قال أبنه عنك ثم تنفس قال أرى فيه القذاة قال فأهرقها
Its isnad is sahih. Malik is the imam, and Ayub bin Habib Zuhri is trustworthy, and Abu Muthanna is Juhani Madani, whom many considered trustworthy, though Ibn Hajar said he was acceptable. The hadith is found in Tirmidhi 4/304, no. 1887, where he said it is hasan sahih, in the chapter on Beverages, on the dislike of blowing, and in Malik 2/625 in the description of the Prophet ﷺ, and in Darimi 2/161, no. 2121.