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).  

بَعَثَ النَّبِيُّ ﷺ خَيْلاً قِبَلَ نَجْدٍ فَجَاءَتْ بِرَجُلٍ مِنْ بَنِي حَنِيفَةَ يُقَالُ لَهُ ثُمَامَةُ بْنُ أُثَالٍ فَرَبَطُوهُ بِسَارِيَةٍ مِنْ سَوَارِي الْمَسْجِدِ فَخَرَجَ إِلَيْهِ النَّبِيُّ ﷺ فَقَالَ أَطْلِقُوا ثُمَامَةَ فَانْطَلَقَ إِلَى نَخْلٍ قَرِيبٍ مِنَ الْمَسْجِدِ فَاغْتَسَلَ ثُمَّ دَخَلَ الْمَسْجِدَ فَقَالَ أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ  

Abu Hurairah said “ The Apostle of Allaah ﷺ sent some horsemen to Najd and they brought a man of the Banu Hanifah called Thumamah bint Uthal who was the chief of the people of Al Yamamah and bound him to one of the pillars of the mosque. The Apostle of Allaah ﷺ came out to him and said “What are you expecting, Thumamah?”. He replied “I expect good, Muhammad. If you kill (me), you will kill one whose blood will be avenged, if you show favor, you will show it to one who is grateful and if you want property and ask you will be given as much of it as you wish. The Apostle of Allaah ﷺ left him till the following day and asked him ”What are you expecting, Thumamah?” He repeated the same words (in reply). The Apostle of Allaah ﷺleft him till the day after the following one and he mentioned the same words. The Apostle of Allaah ﷺ then said “Set Thumamah free.” He went off to some palm trees near the mosque. He took a bath there and entered the mosque and said “I testify that there is no god but Allaah and I testify that Muhammd is His servant and His apostle. He then narrated the rest of the tradition. The narrator ‘Isa said “Al Laith narrated to us”. He said “a man of respect and reverence.”  

أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ يَقُولُ بَعَثَ رَسُولُ اللَّهِ ﷺ خَيْلاً قِبَلَ نَجْدٍ فَجَاءَتْ بِرَجُلٍ مِنْ بَنِي حَنِيفَةَ يُقَالُ لَهُ ثُمَامَةُ بْنُ أُثَالٍ سَيِّدُ أَهْلِ الْيَمَامَةِ فَرَبَطُوهُ بِسَارِيَةٍ مِنْ سَوَارِي الْمَسْجِدِ فَخَرَجَ إِلَيْهِ رَسُولُ اللَّهِ ﷺ فَقَالَ مَاذَا عِنْدَكَ يَا ثُمَامَةُ قَالَ عِنْدِي يَا مُحَمَّدُ خَيْرٌ إِنْ تَقْتُلْ تَقْتُلْ ذَا دَمٍ وَإِنْ تُنْعِمْ تُنْعِمْ عَلَى شَاكِرٍ وَإِنْ كُنْتَ تُرِيدُ الْمَالَ فَسَلْ تُعْطَ مِنْهُ مَا شِئْتَ فَتَرَكَهُ رَسُولُ اللَّهِ ﷺ حَتَّى إِذَا كَانَ الْغَدُ ثُمَّ قَالَ لَهُ مَا عِنْدَكَ يَا ثُمَامَةُ فَأَعَادَ مِثْلَ هَذَا الْكَلاَمِ فَتَرَكَهُ رَسُولُ اللَّهِ ﷺ حَتَّى كَانَ بَعْدَ الْغَدِ فَذَكَرَ مِثْلَ هَذَا فَقَالَ رَسُولُ اللَّهِ ﷺ أَطْلِقُوا ثُمَامَةَ فَانْطَلَقَ إِلَى نَخْلٍ قَرِيبٍ مِنَ الْمَسْجِدِ فَاغْتَسَلَ فِيهِ ثُمَّ دَخَلَ الْمَسْجِدَ فَقَالَ أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ وَسَاقَ الْحَدِيثَ قَالَ عِيسَى أَخْبَرَنَا اللَّيْثُ وَقَالَ ذَا ذِمٍّ