صحيح البخاري
Sahih Bukhari
كتاب العتق
The Book of Manumission (of Slaves)
باب الخطإ والنسيان فى العتاقة والطلاق ونحوه، ولا عتاقة إلا لوجه الله:
Chapter. What is said about manumission and divorce by mistake or forgetfulness. Manumission of slave should be for Allah’s sake only.