Sunan Ibn Majah, Hadith 1958 ⓘ
It was narrated from 'Aishah: that the Messenger of Allah set Safiyyah free, and made her ransom her dowry, and he married her.
حَدَّثَنَا حُبَيْشُ بْنُ مُبَشِّرٍ، حَدَّثَنَا يُونُسُ بْنُ مُحَمَّدٍ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ أَيُّوبَ، عَنْ عِكْرِمَةَ، عَنْ عَائِشَةَ، . أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ أَعْتَقَ صَفِيَّةَ وَجَعَلَ عِتْقَهَا صَدَاقَهَا وَتَزَوَّجَهَا .
also referenced under: Book 9, Hadith 2034 (In-Book) & Volume 3, Book 9, Hadith 1958 (DarusSalam)