Ayyash bin Abi Rabia (r.a.)
“Ayyash” is the name of a Companion who was close to the Prophet. This word, which means “having a nice state, living healthily and well-off”, is also used in the sense of “cereal seller and baker”.
Hz. Ayyash was one of the first lucky people who accepted the invitation to Islam. He was among those who participated in the luminous caravan of Islam in the first days when the Prophet proclaimed the divine religion. He was present with his wife Asma in the second group that migrated to Abyssinia because of the tortures of the polytheists. When they returned from Abyssinia, the second migration began: the journey to Madinah. 
The Prophet was still in Makkah. He allowed the believers to migrate to Madinah. Hz. Umar, who was one of the first people who left Makkah, performed a prayer of two rak'ahs in the Kaaba in front of the astonished polytheists. He set off by challenging them as follows: "If you want to make your mother cry, widow your wife and orphan your children, come and meet me behind that valley." Hz. Ayyash bin Abi Rabia and Hz. Hisham Bin As accompanied him. Later, they set off for Madinah with a group of 20 people including those who joined them afterwards.
When Abu Jahl, the leader of the unbelieving band, heard that Ayyash, his step maternal uncle, had left Makkah, he followed them with his brother Harith; he caught up with them in Madinah. With his insidious plan, he wanted to deceive Ayyash, persuade him to return to Makkah and torture him there.
Abu Jahl approached the migrating Muslims and found Ayyash. He provoked the sense of compassion of Ayyash. He said, "Your mother vowed that she would not combe her hair and would not sit in the shade until you returned. Go and save her"
Feeling that Ayyash started to relent, Hz. Umar intervened. He wanted to warn Ayyash. He said, "O Ayyash! I swear that they are trying to fool you! They want to take you to Makkah and make you abandon your religion. Do not believe them!"
Hz. Ayyash loved his mother very much. He also stated that he made ends meet with the help of Umar. He said,
"My mother vowed. I cannot contradict her. I am a friend of yours; I live based on your wealth." In fact, he had migrated in accordance with the order of Allah and His Messenger. The consent of Allah was obvious. The rights of parents came after that. Hz. Umar warned him again: "I am one of the rich people of my tribe. I will give you half of my wealth if you do not go with them." However, Ayyash was determined to go. When he insisted, Hz. Umar gave him his camel and said to him, "If you suspect them, get on the camel and escape from them."
The Muslims who were there did not want Ayyash to leave. Hz. Ayyash was going to face the trouble of not acting in accordance with consultation. He set off with Abu Jahl and his brother. When they approached Makkah, the trick of the polytheists began to appear. They asked Ayyash who was following them to ride in front of them. As soon as he started to ride at the front, they jumped on him and tied him tightly; then, they took him to Makkah. Abu Jahl began to torture him. At first, he hit him 100 times with a stick. Then, he imprisoned Ayyash without giving him bread and water. He wanted to intimidate the other Companions who intended to migrate.
Hz. Ayyash made a mistake. The other Muslims did not think good things about him. They were worried that he would return from his religion. However, it was stated in a verse that was sent down later that those who persecuted their own souls would be forgiven. 
The Prophet prayed every day after the morning prayer for the rescue of the Muslims who could not leave Makkah after migrating and who were persecuted by the polytheists: "O Allah! Save Salama bin Hisham, Ayyash bin Abi Rabia and the other weak Muslims who are tortured." 
On the other hand, the Prophet was looking for a way to save them. One day, he asked his Companions, "Who will save the Muslims who are under torture?" Walid bin Walid, who had just returned from Makkah said, "I will save them and bring them to you." When he arrived in Makkah, he learned from a woman where they were kept. He went there at night. He cut the rope that tied them and saved them. They traveled on foot uninterruptedly. They arrived in Madinah. Hz. Walid's fingers were torn. However, the joy of saving his brothers made him forget all of the troubles. 
The Islamic State was established in Madinah. The Prophet was the head of the first Islamic State. It was time for the relationships with other states. He wrote letters to invite the heads of other states and tribal chieftains to the true religion and sent one to each of them through envoys. He sent Ayyash to Masruh and Nuaym bin Abdil-Kulal, the heads of the Himyar tribe living in South Yemen.
The prophet chose the people whom he sent to the heads of state and tribe from among the Companions who were strong, knowledgeable and shrewd in foreign relations. He told and explained them what to do, how to behave and even what to wear in detail.
After giving Ayyash a letter to invite the people of Himyar to Islam, he gave Ayyash the following advice:
"Do not enter their land at night. Make wudu after waiting until the morning. Perform a prayer of two rak'ahs. Ask salvation and acceptance from Allah. Take refuge in Allah. Take my letter in your right hand, give them with your right hand and from the right side. When they accept you, read them the chapter of al-Bayyina. The evidence they will show you will be useless. The gilded books they will give you will have no light. When they read something to you in their own language, say 'translate it'. After saying 'Allah is enough for me', read the following verse: Now then, for that (reason), call (them to the Faith), and stand steadfast as thou art commanded nor follow thou their vain desires; but say: "I believe in the Book which Allah has sent down; and I am commanded to judge justly between you. Allah is Our Lord and your Lord. For us (is the responsibility for) Our deeds, and for you for your deeds. There is no contention between us and you. Allah will bring us together, and to Him is (Our) final goal.'" 
With these words, the Prophet recommended "telling the truth", which is the first condition of conveying the message of Islam. He told Ayyash how to treat them when they became Muslims as follows:
"When they become Muslims, ask them to give you the three staffs before which they prostrate all together. [He told Ayyash from which they were made of.] They will bring them to you. Burn them in the middle of the market."
With these words, the Prophet wanted them to cut off all of their relationship with their previous religion. He stated that everything belonging to the wrong had to be destroyed when the truth came.
Hz. Ayyash went to Himyar. He acted according to the instructions of the Prophet. After Ayyash left, the leaders of Himyar stated that they became Muslims by sending a letter with an envoy.
Hz. Ayyash, who participated in the conquest of Syria and fought heroically during the caliphate of Hz. Abu Bakr, died in Makkah after returning from Damascus.
May Allah be pleased with him!
Usdul-Ghaba, 4: 161.
az-Zumar, 53, 55.
Tabaqat, 4: 130.