Muwatta Malik 1477
موطأ مالك#1477Sahihحَدَّثَنِي 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 from A'isha, the wife of the Prophet, may Allah bless him and grant him peace, that the Messenger of Allah, may Allah bless him and grant him peace, 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
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 38:14