Narrated Abdullah ibn Abbas:

The verse "And no Prophet (ﷺ) could (ever) be false to his trust" was revealed about a red velvet. When it was found missing on the day of Badr, some people said; Perhaps the Messenger of Allah (ﷺ) has taken it. So Allah, the Exalted, sent down "And no prophet could (ever) be false to his trust" to the end of the verse. Abu Dawud said: In the word yaghulla the letter ya has a short vowel a.

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ، حَدَّثَنَا خُصَيْفٌ، حَدَّثَنَا مِقْسَمٌ، مَوْلَى ابْنِ عَبَّاسٍ قَالَ قَالَ ابْنُ عَبَّاسٍ رضى الله عنهما نَزَلَتْ هَذِهِ الآيَةُ ‏{‏ وَمَا كَانَ لِنَبِيٍّ أَنْ يَغُلَّ ‏}‏ فِي قَطِيفَةٍ حَمْرَاءَ فُقِدَتْ يَوْمَ بَدْرٍ فَقَالَ بَعْضُ النَّاسِ لَعَلَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَخَذَهَا فَأَنْزَلَ اللَّهُ عَزَّ وَجَلَّ ‏{‏ وَمَا كَانَ لِنَبِيٍّ أَنْ يَغُلَّ ‏}‏ إِلَى آخِرِ الآيَةِ ‏.‏ قَالَ أَبُو دَاوُدَ يَغُلَّ مَفْتُوحَةُ الْيَاءِ ‏.‏