‘Umair client of Abul Lahm said

I was present at Khaibar along with my masters who spoke about me to God's Messenger, telling him that I was a slave. He ordered that I should have a sword girded on me, and I was trailing it.* He then ordered that I should be given some inferior goods. I submitted to him a spell with which I used to treat people who were possessed and he ordered me to reject part of it and retain part. *Either because he was a small man, or because he was young. Tirmidhi and Abu Dawud transmitted it, but the latter's version ended at “goods”.