The Prophet ﷺ freed Safiyyah and made her emancipation her dowry.
حدثنا عمرو بن عون أخبرنا أبو عوانة عن قتادة وعبد العزيز بن صهيب
أن النبي ﷺ أعتق صفية وجعل عتقها صداقها
Reported by Muslim in the Book of Marriage, chapter on the merit of freeing one's female slave and then marrying her, hadith no. 85/1365, after 1427, from the hadith of Abu Awana. And Bukhari in the Book of Fear, chapter on setting out early and praying at dawn in the dim light and prayer at the time of a raid and battle, hadith no. 947, from the hadith of Abdul-Aziz bin Suhayb, with the same wording.