Mahmud bin Rabi' remembered that the Prophet spat into a bucket from a well that belonged to them. (Using translation from Ibn Mājah 660)
عَنْ مَحْمُودِ بْنِ رَبِيعٍ وَقَدْ كَانَ عَقَلَ مَجَّةً مَجَّهَا رَسُولُ اللهِ ﷺ فِي وَجْهِهِ مِنْ دَلْوٍ مِنْ بِئْرٍ لَهُمْ