Sunan an-Nasa'i 723
سنن النسائي#723Sahihأَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " الْبُصَاقُ فِي الْمَسْجِدِ خَطِيئَةٌ وَكَفَّارَتُهَا دَفْنُهَا " .
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
Scholarly Authentication
The label above is the grade most of these scholars gave, each scholar counted once — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. When they judged only its chain of narrators (“Isnaad”), the label says “Sound chain”. Each scholar's own wording:
Our source also lists this ruling under Abu Ghuddah, the editor of the printed edition it was taken from. It is al-Albani's ruling printed again, so it is counted once.
In-book reference: 8:36