Abu Dawud Book 12, Hadith Number 2899.
Chapter : Shares of the relatives on the maternal side.
Narated By Abdullah ibn Abbas : A man died leaving no heir but a slave whom he had emancipated. The Apostle of Allah (PBUH) asked: Has he any heir? They replied: No, except a slave whom he had emancipated. The Apostle of Allah (PBUH) assigned his estate to him (the emancipated slave).