Zaid bin Arkam (may Allah be pleased with him) reports that the Companions of the Prophet (peace and blessings be upon him) asked him:
“Oh Prophet of Allah, what is this sacrifice?” He said: “it is the way of your fore father Ibrahim (peace and blessings be upon him).” They asked: “what (reward) is for us therein?” He replied: “There is a reward for every hair.” They asked: “For the wool, Oh Prophet of Allah?” He replied: “There is one reward for every strand of wool.”
[Related by Ahmed and Ibn Majah]
Was Salam
Abu Zaynah
Islamopedia 