ʿAli remained behind the Prophet ﷺ during the Ghazwa of Khaibar as he was suffering from eye trouble. He then said, "(How can) I remain behind the Prophet ﷺ ," and followed him. So when he slept on the night of the conquest of Khaibar, the Prophet ﷺ said, "I will give the flag tomorrow, or tomorrow the flag will be taken by a man who is loved by Allah and His Apostle , and (Khaibar) will be conquered through him, (with Allah's help)" While every one of us was hopeful to have the flag, it was said, "Here is ʿAli" and the Prophet ﷺ gave him the flag and Khaibar was conquered through him (with Allah's Help).
كَانَ عَلِيٌّ ؓ تَخَلَّفَ عَنِ النَّبِيِّ ﷺ فِي خَيْبَرَ وَكَانَ رَمِدًا فَقَالَ أَنَا أَتَخَلَّفُ عَنِ النَّبِيِّ ﷺ فَلَحِقَ فَلَمَّا بِتْنَا اللَّيْلَةَ الَّتِي فُتِحَتْ قَالَ لأُعْطِيَنَّ الرَّايَةَ غَدًا أَوْ لَيَأْخُذَنَّ الرَّايَةَ غَدًا رَجُلٌ يُحِبُّهُ اللَّهُ وَرَسُولُهُ يُفْتَحُ عَلَيْهِ فَنَحْنُ نَرْجُوهَا فَقِيلَ هَذَا عَلِيٌّ فَأَعْطَاهُ فَفُتِحَ عَلَيْهِ