the Messenger of Allah said: "To spit in the Masjid is a sin, and burying it is its atonement."
Jami` at-Tirmidhi Book 6, Hadith 29
← Previous Hadith the Messenger of Allah said: "When you are in Salat then do not spit on your right, but behind you or toward your left, or under your left foot."

Jami` at-Tirmidhi Book 6, Hadith 28 Next Hadith → "We prostrated with the Messenger of Allah in: 'Read! In the Name of your Lord' and 'When the heaven is split asunder.'"

Jami` at-Tirmidhi Book 6, Hadith 30