The verse "And no Prophet 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.
ابْنُ عَبَّاسٍ ؓ نَزَلَتْ هَذِهِ الآيَةُ { وَمَا كَانَ لِنَبِيٍّ أَنْ يَغُلَّ } فِي قَطِيفَةٍ حَمْرَاءَ فُقِدَتْ يَوْمَ بَدْرٍ فَقَالَ بَعْضُ النَّاسِ لَعَلَّ رَسُولَ اللَّهِ ﷺ أَخَذَهَا فَأَنْزَلَ اللَّهُ ﷻ { وَمَا كَانَ لِنَبِيٍّ أَنْ يَغُلَّ } إِلَى آخِرِ الآيَةِ