Sahih al-Bukhari 174
صحيح البخاري#174Sahihوَقَالَ أَحْمَدُ بْنُ شَبِيبٍ حَدَّثَنَا أَبِي، عَنْ يُونُسَ، عَنِ ابْنِ شِهَابٍ، قَالَ حَدَّثَنِي حَمْزَةُ بْنُ عَبْدِ اللَّهِ، عَنْ أَبِيهِ، قَالَ كَانَتِ الْكِلاَبُ تَبُولُ وَتُقْبِلُ وَتُدْبِرُ فِي الْمَسْجِدِ فِي زَمَانِ رَسُولِ اللَّهِ صلى الله عليه وسلم فَلَمْ يَكُونُوا يَرُشُّونَ شَيْئًا مِنْ ذَلِكَ.
And narrated Hamza bin 'Abdullah:My father said. "During the lifetime of Allah's Apostle, the dogs used to urinate, and pass through the mosques (come and go), nevertheless they never used to sprinkle water on it (urine of the dog)
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: 4:40