Abu Jandal (r.a.)
The Prophet (pbuh) set off for the Kaaba for umrah with 1400 Companions upon a dream he saw. When the polytheists heard this, they decided not to allow the Muslims to enter the Kaaba. Thereupon, the Messenger of Allah (pbuh) stopped over in Hudaybiyya. He said to the envoys coming from Makkah, "We did not come here to fight anyone. We have come only to perform umrah, to circumambulate the Kaaba." However, the polytheists insisted. They said that they were determined not to allow the Muslims to enter the Kaaba. After discussing and talking, they decided to make a treaty. The polytheists appointed Suhayl bin Amr for the treaty. Suhayl had not become a Muslim yet at that time, he was a ferocious enemy of Islam. He objected to writing Bismillah and mentioning the Prophet as "the Messenger of Allah". He said, "If we believed that you were the Messenger of Allah, we would not fight you." Suhayl's son Abdullah was also there. Hz. Abdullah became a Muslim in the early years of Islam and was thus subjected to the tortures by his father. This disrespectful behavior of his father against the Messenger of Allah made him very uncomfortable. He lowered his head due to embarrassment. (After the conquest of Makkah, Suhayl also became a Muslim)
Eventually, the terms of the treaty were determined and written. According to this, the polytheists and the Muslims would not fight each other for 10 years, the Muslims would return without circumambulating the Kaaba that year but they would be able to circumambulate the following year. The Prophet would not be able to take the Makkans who wanted to be Muslims with him and he would not prevent his Companions who wanted to live in Makkah. There were some other terms in the treaty.
The terms of the treaty were completed but it had not been signed yet. At that moment, something unexpected took place: A young man shackled from his feet came to the Messenger of Allah dragging the shackles. This man was Abu Jandal, the son of Suhayl bin Amr. Abu Jandal was chained by the polytheists because he had become a Muslim. Suhayl brutally tortured Abu Jandal as he had previously tortured his other son, Abdullah. He got very angry when he saw Abu Jandal. He walked up to his son. He began to hit his face with the prickly branch in his hand. Then he said, "O Muhammad! This is the first person you will give me back according to our treaty." The Prophet said that the treaty had not yet been signed and asked him to leave Abu Jandal out of this treaty. However, Suhayl did not accept it. He said he would not sign the treaty if he did not return his son to him. Then, the Prophet returned him. After that, the treaty was signed.
Suhayl held his son and began to drag him. Abu Jandal addressed the Muslims as follows: "O Muslims! Are you returning me to the polytheists though I came to you as a Muslim? Do you not know that I was tortured? O Muslims! Are you returning me to the polytheists so that they will torture me and make abandon my religion?" The Muslims could not stand his wailing and started to shed tears. The Prophet approached Abu Jandal and consoled him:
“O Abu Jandal! The writing of the peace treaty between us and them was completed. Be patient a bit more and expect its reward from Allah. There is no doubt that Almighty Allah will create a way out for you and for the weak and forbidden Muslims who are near you. We made a peace treaty with these people and we promised them in the name of Allah. We cannot break our promise to them.”
After that, the Messenger of Allah (pbuh) asked Suhayl again to release Abu Jandal. When Suhayl refused it, the Prophet said, "Then, take him under your protection." Suhayl refused this wish of the Messenger of Allah too.
However, Mikraz bin Hafs and Huwaytib bin Abduluzza, who came with Suhayl, said, "O Muhammad! We will take him under our protection for your sake. We will not allow him to be tortured."
Then, Abu Jandal left with his father. After a while, the Prophet departed from Hudaybiyya with his Companions and proceeded to Madinah.
Doubtlessly, behind the things that seem bad, there are so many good things. However, those who could not see the manifestations of divine mercy behind the veil felt sad. As a matter of fact, the Treaty of Hudaybiyya brought about many good things. Abu Basir, who was exposed to torture because he was a Muslim and who found a way to escape, settled in Is Valley in Dhul-Hulayfa. Soon after, Abu Jandal and many other Companions that escaped from Makkah and joined him. These mujahids intercepted the route of Qurayshi trade and harmed the polytheists a lot. Finally, the polytheists sent a message to the Prophet and said, "For Allah's sake, for the sake of kinship, tell them that anybody who comes to you from now on will be safe and secure; he will not be returned." Thereupon, the Prophet wrote a letter to Abu Basir stating that they could return to their families and ordered him not to attack the caravans anymore. The letter of the Messenger of Allah reached Abu Basir while he was in his deathbed. After Abu Basir read the letter, he passed away. Abu Jandal returned to Madinah with the Muslims that were there. They were 70 people.
Abu Jandal, who spent his remaining life in the service to Islam, died in the 18 H during the caliphate of Hz. Umar.
May Allah be pleased with him! 
Sirah, 3: 331, 337; Usdul-Ghaba, 5: 160; Hz. Muhammed ve İslamiyet, 6: 202-206.