Sahih al-Bukhari 462
صحيح البخاري#462Sahihحَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا اللَّيْثُ، قَالَ حَدَّثَنَا سَعِيدُ بْنُ أَبِي سَعِيدٍ، سَمِعَ أَبَا هُرَيْرَةَ، قَالَ بَعَثَ النَّبِيُّ صلى الله عليه وسلم خَيْلاً قِبَلَ نَجْدٍ، فَجَاءَتْ بِرَجُلٍ مِنْ بَنِي حَنِيفَةَ يُقَالُ لَهُ ثُمَامَةُ بْنُ أُثَالٍ، فَرَبَطُوهُ بِسَارِيَةٍ مِنْ سَوَارِي الْمَسْجِدِ، فَخَرَجَ إِلَيْهِ النَّبِيُّ صلى الله عليه وسلم فَقَالَ " أَطْلِقُوا ثُمَامَةَ ". فَانْطَلَقَ إِلَى نَخْلٍ قَرِيبٍ مِنَ الْمَسْجِدِ، فَاغْتَسَلَ ثُمَّ دَخَلَ الْمَسْجِدَ فَقَالَ أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ.
Narrated Abu Huraira:The Prophet (ﷺ) sent some horsemen to Najd and they brought a man called Thumama bin Uthal from Bani Hanifa. They fastened him to one of the pillars of the mosque. The Prophet (ﷺ) came and ordered them to release him. He went to a (garden of) date-palms near the mosque, took a bath and entered the mosque again and said, "None has the right to be worshipped but Allah and Muhammad is His Apostle" (i.e. he embraced Islam)
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: 8:110