Sahih al-Bukhari 406
صحيح البخاري#406Sahihحَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ،. أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم رَأَى بُصَاقًا فِي جِدَارِ الْقِبْلَةِ فَحَكَّهُ، ثُمَّ أَقْبَلَ عَلَى النَّاسِ فَقَالَ " إِذَا كَانَ أَحَدُكُمْ يُصَلِّي، فَلاَ يَبْصُقْ قِبَلَ وَجْهِهِ، فَإِنَّ اللَّهَ قِبَلَ وَجْهِهِ إِذَا صَلَّى ".
Narrated `Abdullah bin `Umar:Allah's Messenger (ﷺ) saw sputum on the wall of the mosque in the direction of the Qibla and scraped it off. He faced the people and said, "Whenever any one of you is praying, he should not spit in front of him because in the prayer Allah is in front of him
Scholarly Authentication
The label above is the grade most of these scholars gave — 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. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 8:58