Abu Hurairah reported,

We set out with the Prophet ﷺ to Khaybar, and Allah granted us victory. We did not take any gold or silver as spoils, only goods, food, and clothing. Then we went on to the valley, and with the Messenger of Allah ﷺ was a slave of his, given to him by a man from Judham named Rifa bin Zayd, of Banu Dubayb.When we camped in the valley, the slave of the Messenger of Allah ﷺ stood up to unload his saddle and was struck by an arrow, which proved fatal.We said, "Congratulations to him on his martyrdom, Messenger of Allah!"The Messenger of Allah ﷺ replied, "Not at all! By the One in whose hand is Muhammad's soul, the cloak he took from the spoils on the day of Khaybar, before they were distributed, is now blazing upon him as fire."The people were alarmed by this. A man came forward with a sandal strap, or two sandal straps, and said, "Messenger of Allah, I took these on the day of Khaybar."The Messenger of Allah ﷺ said, "A strap of fire, or two straps of fire."

عن أبي هريرة قال

خرجنا مع النبي ﷺ إلى خيبر، ففتح الله علينا، فلم نغنم ذهبا ولا ورقا، غنمنا المتاع والطعام والثياب، ثم انطلقنا إلى الوادي، ومع رسول الله ﷺ عبد له، وهبه له رجل من جذام، يدعى رفاعة بن زيد من بني الضبيب، فلما نزلنا الوادي قام عبد رسول الله ﷺ يحل رحله فرمي بسهم، فكان فيه حتفه، فقلنا: هنيئا له الشهادة يا رسول الله! قال رسول الله ﷺ: كلا، والذي نفس محمد بيده! إن الشملة لتلتهب عليه نارا، أخذها من الغنائم يوم خيبر، لم تصبها المقاسم، قال: ففزع الناس، فجاء رجل بشراك أو شراكين، فقال: يا رسول الله! أصبت يوم خيبر، فقال رسول الله ﷺ: شراك من نار، أو شراكان من نار.