(49) باب مَا جَاءَ فِي كَرَاهِيَةِ الْبُزَاقِ فِي الْمَسْجِدِ
Anas bin Malik narrated that :
the Messenger of Allah said: "To spit in the Masjid is a sin, and burying it is its atonement."
Reference: Jami` at-Tirmidhi 572
In-book reference: Book 6, Hadith 29
English translation: Vol. 2, Book 1, Hadith 572