It has been narrated on the authority of Abu Huraira who said:
The Messenger of Allah ( صلی اللہ علیہ وسلم ) 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 ( صلی اللہ علیہ وسلم ) 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 ( صلی اللہ علیہ وسلم ) 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 ( صلی اللہ علیہ وسلم ) 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 ( صلی اللہ علیہ وسلم ) 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 ( صلی اللہ علیہ وسلم ). By Allah, you will not get a single grain of wheat from Yamama until it is permitted by the Messenger of Allah ( صلی اللہ علیہ وسلم ).