Mus’ab bin Umayr (r.a.)
Each one of the Companions, about whom the Messenger of Allah (pbuh) said, “My Companions are like stars; whomever of them you follow you will be rightly guided”  has a life that is full of lessons for us. There are lessons we can take from all Companions. Mus’ab bin Umayr is one of those distinguished people.
This Companion was a young man who was one of the most beloved and respectable people of Makkah. Mus’ab, who was the apple of his family’s eye, was leading a wealthy and pompous life. His parents did whatever he wished. While leading such a dazzling life, Mus’ab was informed about the religion introduced by the Prophet Muhammad (pbuh). He was curious about it and visited the Prophet. After listening to his talk for a while, the light of guidance started to enlighten his heart. After talking to the Prophet for a while, he left. Mus’ab, who entered into the presence of the Messenger of Allah as a polytheist came out as a Muslim. However, he kept it as a secret for a while since he was afraid of the people in his environment. He performed prayers secretly.
However, once, a polytheist saw him performing a prayer and told his family about it. This was a milestone in Mus’ab’s life. Mus’ab, who was loved and respected by Makkans before, was disturbed and oppressed by Makkans. He was imprisoned. Then, he went to Abyssinia with a group of Muslims. He lived there for a while. When he returned, there was nothing different. His family and relatives were hostile to him again.
When the Prophet (pbuh) was talking to his Companions one day, Mus’ab arrived. He greeted them. The Companions felt embarrassed because they could not help him properly. After answering Mus’ab’s greeting, the Prophet (pbuh) said,
“Praise be to Allah who can change the world with all of its inhabitants. Do you see this young man? He used to be the most beloved being of his parents. The love of Allah and His Messenger became superior to the love of his mother and father. He preferred Allah and His Messenger to his parents.” 
Mus’ab bin Umayr, who received this compliment from the Messenger of Allah (pbuh), had sacrificed everything – his house, his pompous life, the pleasures that were difficult to abandon he had for the sake of Allah and His Messenger, his mother, his father… - for the sake of Allah and His Messenger.
This self-sacrificing person attained an unending wealth in return for this; he was appointed as one of the preachers and teachers of Islam in Madinah by the Messenger of Allah (pbuh).
When Islam started to spread fast in Madinah after the First Pledge of Aqaba, the new Muslims there asked the Prophet (pbuh) to send them teachers to teach them Islam. The first teacher was Mus’ab bin Umayr. This Companion, who was a symbol of self-sacrificing, went to Madinah and settled in As’ad bin Zurara’s house and taught the principles of Islam to the people who came to this house. Thus, As’ad’s house become an Islamic school. It was such a blessed place that everybody that went there became a Muslim.
The Muslims whose number increased fast wanted to perform Friday prayer in Madinah. They informed the Messenger of Allah (pbuh) about it and got permission from him. Ansar gathered in Sa’d bin Haythama’s house and the Muslims of Madinah performed the first Friday prayer there under the imamate of Mus’ab.
Afterwards, Mus’ab went to Makkah, visited the Messenger of Allah and told him about the progress in Madinah. When Mus’ab’s mother was informed about this visit, she became very angry and sent the following message to her son:
“Bad Son! How can you visit somebody else before me when you come to Makkah?”
Mus’ab’s answer was as follows:
“I cannot visit anybody before the Messenger of Allah (pbuh).”
Then, Mus’ab got permission from the Prophet and went to see his mother. She said, “Do you still have that your wrong belief?” He said,
“Mom! I follow the religion of Muhammad (pbuh). That religion is the true religion sent by God Almighty.”
Then, he said,
“You know my devotion and love to you. Please believe in Allah and His Messenger, whom I believe in. I really want it sincerely.”
His mother said people would make fun of her if she believed and rejected his offer.
However, she decided not to interfere in the belief of her son after that.
Mus’ab, who remained in Makkah for a while with the Messenger of Allah (pbuh), returned to Madinah afterwards. Once, when he was in Makkah, the Prophet saw him gnawing a bone. He said to the Companions with him, “The parents of that person give him the best food but he prefers to stay with us and put up with hunger.”
Mus’ab, who had such a blessed life, passed away in a way that fit that life. He was given the duty of carrying the standard of the Messenger of Allah in the Battle of Uhud. On the one hand, he was fighting; on the other hand, he was reciting the following verse, which was sent down due to the retreat of some Muslims:
“Muhammad is no more than a messenger: many Were the messenger that passed away before him. If he died or were slain, will ye then Turn back on your heels?...”
Mus’ab, who resisted against the polytheists with his heroic perseverance, was attacked by a polytheist called “Ibn Qamia”. He approached Mus’ab on his horse and severed his hand holding the standard. Mus’ab held the standard with his left hand but his left hand was also severed. This time, Mus’ab tried to hold the standard against his chest by grabbing it with his teeth. A Companion came and held the standard. Actually, he was an angel. He was disguised as Mus’ab and continued fighting. The Messenger of Allah called him but he heard the answer “O Messenger of Allah! I am not Mus’ab”  from the angel. It was understood that Mus’ab had been martyred then. Thereupon, the Prophet (pbuh) recited the following verse in tears:
“Among the Believers are men who have been true to their covenant with Allah: of them some have completed their vow (to the extreme), and some (still) wait: but they have never changed (their determination) in the least.”
When this great Companion was martyred, there was nothing but a piece of cloth to be used as a shroud for him. When his head was covered, his feet were left open. When his feet were covered, his head was left open. Mus’ab, who sacrificed what he loved for Allah, rejoined Allah, whom he loved more than anything else, like that.
May Allah be pleased with him forever!
Kashful-Khafa, 1: 132.
Tabaqat, 3: 116.
Aal-i Imran, 144.
Tabaqat, 3: 121.