Sahih al-Bukhari 8:110
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).
Reference
Sahih al-Bukhari 8:110
In-book reference
Book 8, Hadith 110
Arabic Text
حَدَّثَنَا 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.