I was present at Khaybar with my masters, and they spoke to the Messenger of Allah ﷺ about me. He ordered that I be given a sword to wear, and when I put it on, I found myself dragging it along the ground. He was then informed that I was a slave, so he ordered that I be given some odds and ends from the household goods.
حدثنا بشر بن المفضل عن محمد بن زيد
شهدت خيبر مع سادتي فكلموا في رسول الله ﷺ فأمرني فقلدت سيفا فإذا أنا أجره فأخبر أني مملوك فأمر لي بشيء من خرثي المتاع
Its isnad is sahih. Muhammad bin Zayd is Ibn Muhajir bin Qunfudh, and he is trustworthy, his hadith is found in Muslim. The hadith was narrated by Abu Dawud 3/75 no. 2730 in jihad, on the woman and the slave receiving a portion from the spoils, and Tirmidhi 4/127 no. 1557 in campaigns, whether the slave is given a share, and Nasai in Al-Kubra 4/365 no. 7535 in medicine, on what may be used to treat one afflicted with madness. And Darimi 2/226 no. 2855.