It is narrated from Sayyiduna Usamah bin Akhdari (may Allah be pleased with him) that a man from Banu Shaqrah named Asram was among the group who came to the Messenger of Allah (peace and blessings be upon him). The narrator said: He brought to him (peace and blessings be upon him) an Abyssinian slave whom he had bought in that region, and said: "O Messenger of Allah! I have bought this slave, and I would like you to name him and pray for blessing for him." He (peace and blessings be upon him) said (to the man): "What is your name?" He said: "Asram." He (peace and blessings be upon him) said: "No, rather your name is Zur'ah." Then he (peace and blessings be upon him) said: "For what work do you want him (the slave)?" He said: "I want to make him a herdsman." He (peace and blessings be upon him) said: "Then he is Asim (that is, a protector)," and the Prophet (peace and blessings be upon him) closed his palm.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 520