Ubayda bin Harith (r.a.)
Ubayda (r.a.) was one of the first Muslims. He was martyred at Badr.
When the Messenger of Allah passed by his grave years later, he said, “The nice smell you notice comes from Ubayda's grave.”
Ubayda (r.a.) became a Muslim in the first years of Islam and put up with all of the hardships he encountered. When the order for migration was sent by Allah, he left his hometown and migrated to Madinah.
The only aim of this fortunate mujahid, who joined the Battle of Badr, was "to become a martyr". When the two armies confronted, Utba, Shayba and Walid asked for three mujahids to fight. Three mujahids from Ansar proceeded. However, they said, “We do not want you. We want to fight three people from Children of Abdulmuttalib, our cousins.”
Thereupon, the (pbuh) Prophet said, “Stand up O Ubayda! Stand up O Hamza! Stand up O Ali!”
These three heroes rushed forward. When the polytheists saw them, they became happy. They said, “Yes, you are equal to us.”Then, they started to fight. Hz. Hamza killed Shayba and Hz. Ali killed Walid at once. Ubayda (r.a.) and Utba wounded each other and fell down. Hz. Hamza and Hz. Ali rushed to help Ubayda and killed Utba. They carried Ubayda to the Muslims' ranks.
Ubayda (r.a.) asked the Messenger of Allah “O Messenger of Allah! Am I not a martyr?”
The Prophet said, “Yes, you are.”
Hz. Ubayda became very happy and said, “If Abu Talib had been alive, he would have understood that I deserved to be the person he mentioned more than him and read the following couplet by Abu Talib:
“Do you think we will surrender him to you unless we fight around him by forgetting our families and we are knocked down?”
Thus, Hz. Ubayda sacrificed his life so that the Messenger of Allah would not be harmed; and he attained the rank of martyrdom. He was 63 years old then. He was buried in the place called Safra.
Years later, the Prophet was passing by Safra with his Companions. One of them asked, “O Messenger of Allah! I smell something very nice. What is it?”
The Prophet (pbuh) said, “The grave of Abu Muawiya (Ubayda bin Harith) is here. This smell comes from his grave.” 
May Allah be pleased with him!
Tabaqat, 2: 17; 3: 50-52; Istiab, 2: 444-445.