Mishkat al-Masabih 13 Marriage كتاب النكاح 116

عَنْ عُرْوَةَ عَنْ عَائِشَةَ: أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ لَهَا فِي بَرِيرَةَ: «خُذِيهَا فَأَعْتِقِيهَا» . وَكَانَ زَوْجُهَا عَبْدًا فَخَيَّرَهَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَاخْتَارَتْ نَفسهَا وَلَو كَانَ حرا لم يخيرها

‘Urwa told on’ A’isha’s authority that God’s Messenger said to her concerning Barira, “Take her and set her free.” Now her husband was a slave, so God’s Messenger gave her her choice and she chose to separate from him; but if he had been free he would not have given her her choice. (Bukhari and Muslim.)