Hadith 2:131
Narrated Anas (RA):
Allah's Messenger (ﷺ) said: "Spitting in the mosque is a sin and its expiation is burying it." [Agreed upon].
وَعَنْ أَنَسٍ - رضى الله عنه - قَالَ : قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ اَلْبُزَاقُ فِي اَلْمَسْجِدِ خَطِيئَةٌ وَكَفَّارَتُهَا دَفْنُهَا } مُتَّفَقٌ عَلَيْهِ