Sunan Ibn Majah, Hadith 660 ⓘ
It was narrated from Zuhri that: Mahmud bin Rabi' remembered that the Prophet spat into a bucket from a well that belonged to them.
حَدَّثَنَا أَبُو مَرْوَانَ، حَدَّثَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ الزُّهْرِيِّ، عَنْ مَحْمُودِ بْنِ الرَّبِيعِ، وَكَانَ، قَدْ عَقَلَ مَجَّةً مَجَّهَا رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ فِي دَلْوٍ مِنْ بِئْرٍ لَهُمْ .
also referenced under: Book 1, Hadith 705 (In-Book) & Volume 1, Book 1, Hadith 660 (DarusSalam)