Abu Burayda reported,

We laid siege to Khaybar. Abu Bakr took the banner and went out, but he came back without victory being granted to him. The next day he took it again, went out, and returned, but again no victory was granted to him. The people suffered great hardship and exhaustion that day.The Messenger of Allah ﷺ said, "Tomorrow I will hand the banner to a man whom Allah and His Messenger love, and who loves Allah and His Messenger. He will not return until victory is granted to him."We spent the night content in ourselves, certain that the conquest would come the next day. When morning came, the Messenger of Allah ﷺ prayed the dawn prayer, then stood up and called for the banner while the people were in their ranks. He summoned Ali, who was suffering from sore eyes, spat into his eyes, and handed him the banner, and victory was granted to him.Burayda said, "And I was among those who stretched their necks hoping for it."

حدثنا زيد بن الحباب حدثني الحسين بن واقد حدثني عبد الله بن بريدة حدثني

أبي بريدة قال

حاصرنا خيبر فأخذ اللواء أبو بكر فانصرف ولم يفتح له ثم أخذه من الغد فخرج فرجع ولم يفتح له وأصاب الناس يومئذ شدة وجهد فقال رسول الله ﷺ إني دافع اللواء غدا إلى رجل يحبه الله ورسوله ويحب الله ورسوله لا يرجع حتى يفتح له فبتنا طيبة أنفسنا أن الفتح غدا فلما أن أصبح رسول الله ﷺ صلى الغداة ثم قام قائما فدعا باللواء والناس على مصافهم فدعا عليا وهو أرمد فتفل في عينيه ودفع إليه اللواء وفتح له قال بريدة وأنا فيمن تطاول لها