I asked, or they asked, "Messenger of Allah, what are these sacrifices?"He replied, "The tradition of your father Ibrahim."They asked, "What do we get from them?"He answered, "For every hair, a good deed."They asked, "Messenger of Allah, what about the wool?"He replied, "For every strand of wool, a good deed."
حدثنا يزيد بن هارون أخبرنا سلام بن مسكين عن عائذ الله المجاشعي عن أبي داود
قلت أو قالوا يا رسول الله ما هذه الأضاحي قال سنة أبيكم إبراهيم قالوا ما لنا منها قال بكل شعرة حسنة قالوا يا رسول الله فالصوف قال بكل شعرة من الصوف حسنة
Its isnad is daif because of Abu Dawud, who here is not Ibn Abu Hind but rather Nafi bin Harith. The hadith was narrated by Ibn Majah, 2/1045, no. 3127, in the chapter on udhiya, the reward of udhiya. Hakim graded it sahih, 2/389, but Dhahabi disagreed with him regarding this Abu Dawud and declared it daif in Misbah Zujaja. See also Bayhaqi, 9/261, though the author of Jawhar Naqi disagreed with him. The hadith appears in al-Mawduat.