Sacrifice (Kitab Al-Dahaya)
Dawud :: Book 15 : Hadith 2821
Narrated AbuSa'id al-Khudri:
I asked the Apostle of Allah (peace_be_upon_him) about the embryo. He replied: Eat it if you wish.
Musaddad's version says: we said: Apostle of Allah, we slaughter a she-camel, a cow and a sheep, and we find an embryo in its womb. Shall we throw it away or eat it? He replied: Eat it if you wish for the slaughter of its mother serves its slaughter.