When we conquered Khaibar, we gained neither gold nor silver as booty, but we gained cows, camels,
goods and gardens. Then we departed with Allah's Messenger (ﷺ) to the valley of Al-Qira, and at that time
Allah's Messenger (ﷺ) had a slave called Mid`am who had been presented to him by one of Banu Ad-Dibbab.
While the slave was dismounting the saddle of Allah's Messenger (ﷺ) an arrow the thrower of which was
unknown, came and hit him. The people said, "Congratulations to him for the martyrdom." Allah's
Apostle said, "No, by Him in Whose Hand my soul is, the sheet (of cloth) which he had taken
(illegally) on the day of Khaibar from the booty before the distribution of the booty, has become a
flame of Fire burning him." On hearing that, a man brought one or two leather straps of shoes to the
Prophet and said, "These are things I took (illegally)." On that Allah's Messenger (ﷺ) said, "This is a strap, or
these are two straps of Fire." - Hadith Al Bukhari 4234 (islam)
Book 64, Hadith 272
Vol. 5, Book 59, Hadith 541