[Machine] Thumamah al-Hanafi was captured, so the Prophet ﷺ used to visit him and say, "What do you have, O Thumamah?" Thumamah would reply, "If you kill, then kill a man of blood, and if you show kindness, then be kind to a grateful person, and if you take something, then give whatever you wish." The companions of the Prophet ﷺ loved to offer ransom and they would say, "What should we do with this man's killing?" One day, the Prophet ﷺ passed by him and he embraced Islam. The Prophet then sent him to the orchard of Abu Talhah and commanded him to bathe. He bathed and prayed two rak'ahs. The Prophet ﷺ said, "Indeed, the Islam of your companion is good."  

أَنَّ ثُمَامَةَ الْحَنَفِيَّ أُسِرَ فَكَانَ النَّبِيُّ ﷺ يَعُودُ إِلَيْهِ فَيَقُولُ «مَا عِنْدَكَ يَا ثُمَامَةُ؟ » فَيَقُولُ إِنْ تَقْتُلْ تَقْتُلْ ذَا دَمٍ وَإِنْ تَمُنَّ تَمُنَّ عَلَى شَاكِرٍ وَإِنْ تُرِدِ الْمَالَ تُعْطَ مَا شِئْتَ قَالَ فَكَانَ أَصْحَابُ النَّبِيِّ ﷺ يُحِبُّونَ الْفِدَاءَ وَيَقُولُونَ مَا نَصْنَعُ بِقَتْلِ هَذَا «فَمَرَّ بِهِ النَّبِيُّ ﷺ يَوْمًا فَأَسْلَمَ فَبَعَثَ بِهِ إِلَى حَائِطِ أَبِي طَلْحَةَ فَأَمَرَهُ أَنْ يَغْتَسِلَ فَاغْتَسَلَ وَصَلَّى رَكْعَتَيْنِ» فَقَالَ رَسُولُ اللَّهِ ﷺ «لَقَدْ حَسُنَ إِسْلَامُ صَاحِبِكُمْ»  

The Messenger of Allah ﷺ sent some horsemen to Najd. They captured a man. He was from the tribe of Banu Hanifa and was called Thumama b. Uthal. He was the chief of the people of Yamama. People bound him with one of the pillars of the mosque. The Messenger of Allah ﷺ came out to (see) him. He said: O Thumama, what do you think? He replied: Muhammad, I have good opinion of you. If you kill me, you will kill a person who has spilt blood. If you do me a favour, you will do a favour to a grateful person. If you want wealth, ask and you will get what you will demand. The Messenger of Allah (may peace be pon him) lefthim (in this condition) for two days, (and came to him again) and said: What do you think, O Thumama? He replied: What I have already told you. If you do a favour, you will do a favour to a grateful person. If you kill me, you will kill a person who has spilt blood. If you want wealth, ask and you will get what you will demand. The Messenger of Allah ﷺ left him until the next day when he (came to him again) and said: What do you think, O Thumama? He replied: What I have already told you. If you do me a favour, you will do a favour to a grateful person. If you kill me, you will kill a person who has spilt blood. If you want wealth ask and you will get what you will demand. The Messenger of Allah ﷺ said: Set Thumama free. He went to a palm-grove near the mosque and took a bath. Then he entered the mosque and said: I bear testimony (to the truth) that there is no god but Allah and I testify that Muhammad is His bondman and His messenger. O Muhammad, by Allah, there was no face on the earth more hateful to me than your face, but (now) your face has become to me the dearest of all faces. By Allah, there was no religion more hateful to me than your religion, but (now) your religion has become the dearest of all religions to me. By Allah, there was no city more hateful to me than your city, but (now) your city has become the dearest of all cities to me. Your horsemen captured me when I intended going for Umra. Now what is your opinion (in the matter)? The Messenger of Allah ﷺ announced good tidings to him and told him to go on 'Umra. When he reached Mecca, somebody said to him: Have you changed your religion? He said: No! I have rather embraced Islam with the Messenger of Allah ﷺ. By Allah, you will not get a single grain of wheat from Yamama until it is permitted by the Messenger of Allah ﷺ. (Using translation from Muslim 1764a)  

أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ يَقُولُ بَعَثَ رَسُولُ اللَّهِ ﷺ خَيْلًا 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 «مَا عِنْدَكَ يَا ثُمَامَةُ»؟ قَالَ عِنْدِي يَا مُحَمَّدُ خَيْرٌ إِنْ تَقْتُلْنِي تَقْتُلْ ذَا دَمٍ وَإِنْ تُنْعِمْ تُنْعِمْ عَلَى شَاكِرٍ وَإِنْ كُنْتَ تُرِيدُ الْمَالَ فَسَلْ تُعْطَ مِنْهُ مَا شِئْتَ فَتَرَكَهُ رَسُولُ اللَّهِ ﷺ حَتَّى كَانَ الْغَدُ ثُمَّ قَالَ لَهُ «مَا عِنْدَكَ يَا ثُمَامَةُ»؟ قَالَ مَا قُلْتُ لَكَ إِنْ تُنْعِمْ تُنْعِمْ عَلَى شَاكِرٍ وَإِنْ تَقْتُلْ تَقْتُلْ ذَا دَمٍ وَإِنْ كُنْتَ تُرِيدُ الْمَالَ فَسَلْ تُعْطَ مِنْهُ مَا شِئْتَ فَتَرَكَهُ رَسُولُ اللَّهِ ﷺ حَتَّى كَانَ بَعْدَ الْغَدِ فَقَالَ لَهُ «مَا عِنْدَكَ يَا ثُمَامَةُ»؟ فَقَالَ عِنْدِي مَا قُلْتُ لَكَ إِنْ تُنْعِمْ تُنْعِمْ عَلَى شَاكِرٍ وَإِنْ تَقْتُلْ تَقْتُلْ ذَا دَمٍ وَإِنْ كُنْتَ تُرِيدُ الْمَالَ فَسَلْ تُعْطَ مِنْهُ مَا شِئْتَ فَقَالَ رَسُولُ اللَّهِ ﷺ «أَطْلِقُوا ثُمَامَةَ» فَانْطَلَقَ إِلَى نَخْلٍ قَرِيبٍ مِنَ الْمَسْجِدِ فَاغْتَسَلَ ثُمَّ دَخَلَ الْمَسْجِدَ فَقَالَ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ يَا مُحَمَّدُ وَاللَّهِ مَا كَانَ عَلَى الْأَرْضِ وَجْهٌ أَبْغَضَ إِلَيَّ مِنْ وَجْهِكَ فَقَدْ أَصْبَحَ وَجْهُكَ أَحَبَّ الْوُجُوهِ كُلِّهَا إِلَيَّ وَاللَّهِ مَا كَانَ مِنْ دِينٍ أَبْغَضَ إِلَيَّ مِنْ دِينِكَ فَقَدْ أَصْبَحَ دِينَكَ أَحَبَّ الدِّينِ كُلِّهِ إِلَيَّ وَاللَّهِ مَا كَانَ بَلَدٌ أَبْغَضَ إِلَيَّ مِنْ بَلَدِكَ فَقَدَ أَصْبَحَ بَلَدُكَ أَحَبَّ الْبِلَادِ إِلَيَّ وَإِنَّ خَيْلَكَ أَخَذَتْنِي وَأَنَا أُرِيدُ الْعُمْرَةَ فَمَاذَا تَرَى؟ فَبَشَّرَهُ رَسُولُ اللَّهِ ﷺ وَأَمَرَهُ أَنْ يَعْتَمِرَ فَلَمَّا قَدِمَ مَكَّةَ قَالَ لَهُ قَائِلٌ صَبَوْتَ؟ قَالَ لَا وَلَكِنْ أَسْلَمْتُ مَعَ مُحَمَّدٍ رَسُولِ اللَّهِ ﷺ فَلَا وَاللَّهِ لَا تَأْتِيكُمْ مِنَ الْيَمَامَةِ حَبَّةُ حِنْطَةٍ حَتَّى يَأْذَنَ فِيهَا رَسُولُ اللَّهِ ﷺ  

It was narrated from Qais bin 'Asim that he accepted Islam, and the Prophet commanded him to perform Ghusl with water and lotus leaves. (Using translation from Nasāʾī 188)  

«أَنَّهُ أَسْلَمَ فَأَمَرَهُ النَّبِيُّ ﷺ أَنْ يَغْتَسِلَ بِمَاءٍ وَسِدْرٍ»