Sahih al-Bukhari 132
صحيح البخاري#132Sahihحَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ دَاوُدَ، عَنِ الأَعْمَشِ، عَنْ مُنْذِرٍ الثَّوْرِيِّ، عَنْ مُحَمَّدٍ ابْنِ الْحَنَفِيَّةِ، عَنْ عَلِيٍّ، قَالَ كُنْتُ رَجُلاً مَذَّاءً فَأَمَرْتُ الْمِقْدَادَ أَنْ يَسْأَلَ النَّبِيَّ صلى الله عليه وسلم فَسَأَلَهُ فَقَالَ " فِيهِ الْوُضُوءُ ".
Narrated `Ali:I used to get the emotional urethral discharge frequently so I requested Al-Miqdad to ask the Prophet (ﷺ) about it. Al-Miqdad asked him and he replied, "One has to perform ablution (after it)." (See Hadith No)
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: 3:74