(30) باب الْبُصَاقِ فِي الْمَسْجِدِ
It was narrated that Anas said:
"The Messenger of Allah (ﷺ) said: 'Spitting in the Masjid is a sin, and its expiation is to bury it.'"
Reference: Sunan an-Nasa'i 723
In-book reference: Book 8, Hadith 36
English translation: Vol. 1, Book 8, Hadith 724