It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) married Hazrat Safiyyah (may Allah be pleased with her). Thabit asked, "What did the Prophet (peace and blessings be upon him) give her as mahr (dowry)?" He replied that the Prophet (peace and blessings be upon him) considered her freedom itself as her mahr and married her.