بُلُوغُ الْمَرَامِ
Bulugh al-Maram 1053
Marriage
وَعَنْ أَبِي قَتَادَةَ - رضى الله عنه - أَنَّ اَلنَّبِيَّ - صلى الله عليه وسلم -قَالَ : { إِذَا شَرِبَ أَحَدُكُمْ , فَلَا يَتَنَفَّسْ فِي اَلْإِنَاءِ } مُتَّفَقٌ عَلَيْهِ [1] .
Narrated Abu Qatadah (RA): The Prophet (ﷺ) said: "When one of you drinks, he must not breathe into the vessel." [Agreed upon].
Sunnah.com reference: Book 8, Hadith 102