Who is the Companion who was nicknamed "Hami al-Dabr" (Protector of the Rear), and why?

The noble Companion Asim ibn Thabit ibn Abi al-Aqlah was given the epithet "Protector of the Bees" (Hami ad-Dabr) because, during the expedition of Ar-Raji', when the polytheists surrounded him and his companions, he refused to descend [from his position] under the covenant of a disbeliever and fought until he was killed. When the polytheists wanted to take his head to sell it, the "dabr" (bees or wasps) prevented them from approaching him, and then a wadi (valley or torrent) came and carried away his body. Umar ibn al-Khattab commented on this, saying that Allah protected Asim after his death just as he abstained from the polytheists during his life.