Musannaf Ibn Abi Shayba 28:678

Hafs ibn Ghiyath narrated to us, from Muhammad ibn Zayd, from Umayr, the freed slave of Abu al-Lahm, who said: I witnessed Khaybar while I was an enslaved servant. When they conquered it, the Prophet, may Allah bless him and grant him peace, gave me a sword and said, "Gird this on." He also gave me some of the miscellaneous goods, but he did not assign me a share.