حَدَّثَنِي مَالِكٌ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم سُئِلَ عَنِ الرِّقَابِ أَيُّهَا أَفْضَلُ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَغْلاَهَا ثَمَنًا وَأَنْفَسُهَا عِنْدَ أَهْلِهَا " .
Malik related to me from Hisham ibn Urwa from his father fromA'isha, the wife of the Prophet, may Allah bless him and grant himpeace, that the Messenger of Allah, may Allah bless him and grant himpeace, was asked what was the most excellent kind of slave to free.The Messenger of Allah, May Allah bless him and grant him peace,answered, "The most expensive and the most valuable to his master." Translation Not Available
Book Ref: Muwatta Imam Malik Book 38 Hadith 1480
Web Ref: Muwatta Imam Malik Book 38 Hadith 15