Jabbar bin Sahr (r.a.)
Hz. Jabbar was from Madinah. He was present in the Second Pledge of Aqaba. He participated in all wars with the Prophet beginning with the Battle of Badr.
After Khaybar was conquered, Prophet appointed him to collect tax in Khaybar. Jabbar continued the same duty during the caliphate of Hz. Abu Bakar and Hz. Umar.
Hz. Jabbar was distinguished with his devotion to the Prophet. Whenever the Messenger of Allah wanted something to done, he would immediately say, "I will do it." During a journey, the Prophet (pbuh) said, "Can anyone go before us and fill the cans with water?" Hz. Jabbar stood up at once and said, "O Messenger of Allah! I will go." The Prophet was pleased with his devotion. Hz. Jabbar narrates what happened afterwards as follows:
"I got up immediately and filled the cans with water. However, I was very tired. I could not put up with it any more. I fell asleep there. After a while, I heard someone say, 'O the owner of the pool!' I turned round and saw the Messenger of Allah coming. I stood up at once. The Messenger of Allah said, 'Take the water container and follow me.' We made wudu and performed the prayer. The Messenger of Allah took me to his right side with his blessed hand. We prayed together. Soon, the other Companions caught up with us."
Hz. Jabbar died during the caliphate of Hz. Uthman in 30 H.
May Allah be pleased with him! 
Tabaqat, 3: 576; Musnad, 3: 421.