Musnad Ahmad 32:997

Yunus narrated to us, Hammad—meaning Ibn Zayd—narrated to us, from Thabit and Abd al-Aziz ibn Suhayb, from Anas, who said: The Messenger of Allah (ﷺ) prayed the morning prayer in the darkness of the end of the night. Then he said: "Allah is the Greatest! Khaybar is ruined. Indeed, when we descend into the courtyard of a people, evil is the morning of those who have been warned." He said: So they came out running in the streets, saying: "Muhammad and the army!" He said: So the Messenger of Allah (ﷺ) overcame them, killed their fighters, and took their offspring captive. Safiyyah became the share of Dihyah al-Kalbi, then she later came to the Messenger of Allah (ﷺ), so he married her and made her dowry her emancipation. He said: Abd al-Aziz ibn Suhayb said to him: "O Abu Muhammad, did you ask Anas what he gave her as a dowry?" Anas said to you: "He gave her herself as a dowry." Thabit laughed and said: "Yes."