Sahih al-Bukhari 6111
صحيح البخاري#6111Sahihحَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا جُوَيْرِيَةُ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ ـ رضى الله عنه ـ قَالَ بَيْنَا النَّبِيُّ صلى الله عليه وسلم يُصَلِّي رَأَى فِي قِبْلَةِ الْمَسْجِدِ نُخَامَةً، فَحَكَّهَا بِيَدِهِ، فَتَغَيَّظَ ثُمَّ قَالَ " إِنَّ أَحَدَكُمْ إِذَا كَانَ فِي الصَّلاَةِ فَإِنَّ اللَّهَ حِيَالَ وَجْهِهِ، فَلاَ يَتَنَخَّمَنَّ حِيَالَ وَجْهِهِ فِي الصَّلاَةِ ".
Narrated `Abdullah bin `Umar:While the Prophet (ﷺ) was praying, he saw sputum (on the wall) of the mosque, in the direction of the Qibla, and so he scraped it off with his hand, and the sign of disgust (was apparent from his face) and then said, "Whenever anyone of you is in prayer, he should not spit in front of him (in prayer) because 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: 78:138