Thumama was one of the well-known leaders of a tribe called Hanifa, living in Yamamah in Arabia during the seventh century (the area around Riyadh today). The city of Makkah was dependant upon Thumama’s tribe for their grain supplies. He had not concerned himself with the problems that the tribe of Quraysh in Makkah had with one of their sons, Muhammad . However, when Muhammad sent a letter to him directly, suggesting that he should become Muslim, he became enraged. He started to send men to attack the Muslims in their city of Madinah. When he captured them, he ordered that they be put to a slow painful death. He even plotted to kill The Prophet , although the plan failed, as a distant uncle of Thumama got word The Prophet to warn him. These war-like actions meant that The Prophet had no alternative but to give orders to capture Thumamah.

On one occasion, Thumamah was on his way to the annual Hajj in Makkah and was captured by the Muslims, who brought him to the mosque of The Prophet . The Prophet ordered that Thumamah be kept as a prisoner of war, so he was fastened to one of the pillars of the mosque. The Prophet said to his companions, “Treat him well in his captivity.” He also said, “Gather all the food that you have and send it to him.” So they used to send to him milk from The Prophet ’s camel.

This was the dialogue between The Prophet and the man who was captured and whose aim was to kill him:

After Thumamah has eaten his fill, The Prophet asked, “What have you got, Thumama?” He replied, “All is well with me.  Should you kill me you will kill a person who has already killed someone else before.  Should you set me free, you will be doing a favour to someone who will be grateful to you.  Should you seek money then ask and you shall be granted the amount you wish.” Thumamah was prepared to meet his fate with dignity, so The Prophet left him till the next day. Then he came and asked him, “What have you got, Thumama?” He replied, “What I have told you before. Should you set me free, you will be doing a favour to someone who will be grateful to you.  Should you kill me you will kill a person who has already killed someone else before.   Should you seek money then ask and you shall be granted the amount you wish.”  So he left him till the next day. 

All the while, Thumamah was being treated and fed well. From his position in the mosque he could see the way the Muslims were living, how they prayed, how they treated their poor who lived in the mosque with Thumamah. Then The Prophet came and asked him, “What have you got, Thumama?” He replied, “What I have told you before. Should you set me free, you will be doing a favor to someone who will be grateful to you.  Should you kill me you will kill a person who has already killed someone else before.   Should you seek money then ask and you shall be granted the amount you wish.” So The Prophet said, “Release Thumama.”

Upon reaching the outskirts of the city he stopped at a garden that had water. He spent some time thinking, then he took a bath and returned to the mosque and said, “I bear witness that there is no god to be worshiped but Allah, and that Muhammad is the Messenger of Allah”.  He continued, “By Allah, O Muhammad !  There was no face on the surface of the earth I disliked more than yours, but now your face has become the most beloved face to me.  By Allah, there was no way I disliked more than yours, but now it is the most beloved way to me.  By Allah, there was no town I disliked more than yours was, but now it is the most beloved town to me.” 

He continued, "I killed some of your followers earlier. What should I do to pay for that?" The Prophet replied, "Don't worry, Thumamah, by embracing Islam, it absolves you of all past crimes and sins." Upon hearing that, he became happy, and decided to put his life and property at the service of the Message and Islam. He said “Your horsemen arrested me when I was intending to perform the pilgrimage to Makkah, so now what do you think?” The Prophet congratulated him and told him to perform the pilgrimage, but taught him the Islamic way to do so. 

When Thumamah reached Makkah and started to call out the Islamic call “Labayk Allah...” (Allah I am coming) the Makkans were greatly disturbed to hear those prayers publicly recited in defiance of them. Many withdrew their swords in an attempt to kill him, but they stopped when they recognised his identity for fear of his people. At that time much of the food supplies to Makkah came from Yamamah, his homeland. Someone said to him, “You have become a Sabian (people who had left the Arabs religion )?” Thumama replied, “No, but I now follow the best way of life, I have embraced Islam with Muhammad , Messenger of Allah. No, by Allah! Not a single grain of wheat will come to you from Yamama unless The Prophet gives his permission.”

The Prophet 's kind treatment allowed Thumama to realise that his previous hatred of Muslims had been irrational, to the extent that he converted from his religion without any pressure. His Faith was so strong that he cut his ties with Quraysh just because they were fighting The Prophet .  He sacrificed the fortunes that he used to gain from trading and he sacrificed his social ties for the sake of being with The Prophet .

Naturally, the Quraysh were surprised, and upset. They complained to Muhammad , saying “He claims that ties of kinship should be respected, yet he has cut himself off from the Quraysh; he has killed fathers with swords, and is now killing children with hunger.” They ignored the hypocrisy of the fact that when they had the upper hand, they had boycotted Muhammad ’s whole tribe, starving them for three years. Though the Quraysh’s history was one of oppression and persecution, Muhammad exercised mercy. The Prophet wrote to Thumamah to lift the boycott and continue the food suppliers to the Makkahns, which he willingly obeyed. Thus the second instance of economic sanctions in Arabia was lifted at the orders of Prophet Muhammad