Abdullah bin Atik (r.a.)
The spread of the light of Islam worried the Jews along with the polytheists of Makkah. In particular, the Jews of Sons of Nadr could not accept the prophethood of Muhammad (pbuh). They nurtured hatred, jealousy and enmity against the Messenger of Allah. They wanted to put him into a difficult situation by sending their scholars to him. However, the Quran silenced them.
The most ferocious on among the Jews of Sons of Nadr and the one who nurtured enmity against the Messenger of Allah the most was Sallam bin Abi Huqayq. He often disturbed the Messenger of Allah, threatened the Muslims and attempted to kill the Messenger of Allah by instigating the people around the Messenger of Allah against him.
The Companions of the Messenger of Allah could not bear his persecution and threats anymore. Once, they were talking to one another. They listed the enemies of the Messenger of Allah. Sallam bin Abi Huqayq was among them. He was the most ferocious one. It was necessary to kill him. For, he was trying to kill the Messenger of Allah. They talked to the Messenger of Allah regarding the issue and asked permission from him. The Messenger of Allah gave them the permission.
This fierce enemy was killed by Abdullah bin Atik. Abdullah bin Atik, who was one of the heroes of the Companions, belonged to the tribe of Khazraj. Once, he went to Khaybar, the castle and city of the Jews, with four Companions. Their aim was to kill the enemy of the Prophet. They were five people: Abdullah bin Anis, Abu Qatada, Aswad bin Khuzay, Mas'ud bin Sinan and Hz. Abdullah himself.
They entered Khaybar at night. They locked all of the houses in the area where Sallam bin Abi Huqayq was from outside. The house where Sallam stayed was in a high place. It was possible to go there only through stairs. They went up and knocked on the door. When Sallam’s wife asked them who they were, they said, "We are a group of Arabs, we want to see the landlord." They entered the house. They started to fight Sallam and killed him. They did not do anything to his wife and children.
Abdullah bin Atik fell down the stairs when he left Sallam’s house because he could not see very well. His ankle was twisted. His friends carried him on their shoulders, took him outside the city and hid him.
However, they were not sure if Sallam was really dead. He might have been wounded. One of them returned. He entered the crowd that had gathered. She heard that Sallam's wife say, "He died." He returned with joy and gave his friends the good news. 
When Abdullah bin Atik entered into the presence of the Messenger of Allah, he complimented Abdullah. He spread his blessed hand on Abdullah’s twisted ankle. Abdullah’s leg healed as if it had not been twisted at all. 
Abdullah was among the 150 people under the command of Hz. Ali that the Prophet sent in the 9th year of the Migration to the tribe of Tayy so that they would break their idols. The Prophet assigned him the duty to provide weapons and equipment for the soldiers.
His heroism in the Battle of Yamama is famous. This battle happened during the time of Abu Bakr. Musaylima, the fake prophet, started to disturb the Muslims. An army under the command of Hz. Khalid bin Walid was sent against him. For, he encouraged the apostate movement and disturbed the Muslims. It was necessary for Muslims to be saved from him. There were fierce clashes between the army of Khalid bin Walid and the army of Musaylima. Hz. Abdullah fought heroically in this battle. He did not leave his sword though he was wounded severely and blood gushed forth from his body. Eventually, he became a martyr.
Thus, this great companion, who spent his life in the service of Islam, attained the rank of martyrdom, which he had desired very much, in 12 H. 
Tabaqat, 2: 91
Usdul-Ghaba, 3: 214.
al-Isaba fi Marifatis-Sahaba, 2: 341.