Volume 7 · Book 62 · Hadith 98
Narrated Anas: Allah's Apostle manumitted Safiyya and then married her, and her Mahr was her manumission, and he gave a wedding banquet with Hais (a sort of sweet dish made from butter, cheese and dates).
— Sahih Bukhari, Volume 7, Book 62: Wedlock, Marriage (Nikaah), Hadith #98