Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: "This verse was revealed on the day of Badr: 'It is not for a prophet to act dishonestly (with the spoils)' [Surah Al Imran: 161], concerning a red velvet sheet that went missing on the day of Badr. Some people said: Perhaps the Messenger of Allah (peace and blessings be upon him) took it. So Allah, the Mighty and Majestic, revealed this verse: 'It is not for a prophet to act dishonestly (with the spoils).'"
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11976