It has been narrated on the authority of Ibn Salama. He heard the tradition from his father who said: ....................
So I went to 'Ali, brought him beading him along and he had sore eyes, and I took him to the Messenger of Allah (S), who applied his saliva to his eyes and he got well. The Messenger of Allah (S) gave him the banner (and 'Ali went to meet Marhab in a single combat). The latter advanced chanting: Khaibar knows certainly that I am Marhab, A fully armed and well-tried valorous warrior (hero) When war comes spreading its flames. 'Ali chanted in reply: I am the one whose mother named him Haidar, (And am) like a lion of the forest with a terror-striking countenance. I give my opponents the measure of sandara in exchange for sa' (i. e. return thir attack with one that is much more fierce). The narrator said: 'Ali struck at the head of Mirhab and killed him, so the victory (capture of Khaibar) was due to him.
Amir b. Sa'd b. Abi Waqqas reported on the authority of his father that Muawiya b. Abi Sufyan appointed Sa'd as the Governor and said:
What prevents you from abusing Abu Turab (Hadrat 'Ali), whereupon be said: It is because of three things which I remember Allah's Messenger (s.a.w.a.) having said about him that I would not abuse him and even if I find one of those three things for me, it would be more dear to me than the red camels. I heard Allah's Messenger (s.a.w.a.) say about 'Ali as he left him behind in one of his campaigns (that was Tabuk). 'Ali said to him: Allah's Messenger, you leave me behind along with women and children. Thereupon Allah's Messenger (s.a.w.a.) said to him: Aren't you satisfied with being unto me what Aaron was unto Moses but with this exception that there is no prophethood after me. And I (also) heard him say on the Day of Khaibar: I would certainly give this standard to a person who loves Allah and his Messenger, and Allah and his Messenger love him too. He (the narrator) said: We had been anxiously waiting for it, when he (the Holy Prophet) said: Call 'Ali. He was called and his eyes were inflamed. He applied saliva to his eyes and handed over the standard to him, and Allah gave him victory. (The third occasion is this) when the (following) verse was revealed: "Let us summon our children and your children." Allah's Messenger (s.a.w.a.) called 'Ali, Fatima, Hasan and Husain and said: O Allah, they are my family.
Suhail reported on the authority of Abu Huraira that Allah's Messenger (s.a.w.a.) said on the Day of Khaibar:
I shall certainly give this standard in the hand of one who loves Allah and his Messenger and Allah will grant victory at his hand. Umar b. Khattab said: Never did I cherish for leadership but on that day. I came before him with the hope that I may be called for this, but Allah's Messenger (s.a.w.a.) called 'Ali b. Abu Talib and he conferred (this honour) upon him and said: Proceed on and do not look about until Allah grants you victory, and 'Ali went a bit and then halted and did not look about and then said in a loud voice: Allah's Messenger, on what issue should I fight with the people? Thereupon he (the Prophet) said: Fight with them until they bear testimony to the fact that there is no god but Allah and Muhammad is his Messenger, and when they do that then their blood and their riches are inviolable from your hands but what is justified by law and their reckoning is with Allah.
Sahl b. Sa'd reported that Allah's Messenger (s.a.w.a.) said on the Day of Khaibar:
I would certainly give this standard to a person at whose hand Allah would grant victory and who loves Allah and His Messenger and Allah and His Messenger love him also. The people spent the night thinking as to whom it would be given. When it was morning the people hastened to Allah's Messenger (s.a.w.a.) all of them hoping that that would be given to him. He (the Holy Prophet) said: Where is 'Ali b. Abu Talib? They said: Allah's Messenger, his eyes are sore. He then sent for him and he was brought and Allah's Messenger (s.a.w.a.) applied saliva to his eyes and invoked blessings and he was all right, as if he had no ailment at all, and conferred upon him the standard. 'Ali said: Allah's Messenger, I will fight them until they are like us. Thereupon he (the Holy Prophet) said: Advance cautiously until you reach their open places, thereafter invite them to Islam and inform them what is obligatory for them from the rights of Allah, for, by Allah, if Allah guides aright even one person through you that is better for you than to possess the most valuable of the camels.
Salama b. Akwa' reported that it was 'Ali whom Allah's Apostle (S) left behind him (in the charge of his family and the Islamic State) on the occasion of the campaign of Khaibar, and his eyes were inflamed and he said:
Is it for me to remain behind Allah's Messenger (s.a.w.a.)? So he went forth and rejoined Allah's Apostle (S) and on the evening of that night (after which) next morning Allah granted victory. Allah's Messenger (s.a.w.a.) said: I will certainly give this standard to a man whom Allah and His Messenger love. or he said: Who loves Allah or His Messenger and Allah will grant him victory through him, and, lo, we saw 'Ali whom we least expected (to be present on that occasion). They (the Companions) said: Here is 'Ali. Thereupon Allah's Messenger (may peace be upon hin) gave him the standard. Allah granted victory at his hand.