وعن أبي علي سويد بن مقرن رضي الله عنه
قال: لقد رأيتني سابع سبعة من بني مقرن ما لنا خادم إلا واحدة لطمها أصغرنا فأمرنا رسول الله صلى الله عليه وسلم: أن نعتقها
I was the seventh child of Banu Muqarrin and we had only one slave-girl. When the youngest of us once happened to slap her (on the face) the Messenger of Allah (sallallahu alayhi wa sallam) ordered us to set her free.
Riyad as-Salihin 1603, Book 18, The Book of the Prohibited actions, Hadith 93. 1 min read