Narrated Sahl bin Sa`d:
That he heard the Prophet (s.a.w.a.) on the day (of the battle) of Khaibar saying, "I will give the flag to a person at whose hands Allah will grant victory." So, the companions of the Prophet (s.a.w.a.) got up, wishing eagerly to see to whom the flag will be given, and everyone of them wished to be given the flag. But the Prophet asked for `Ali. Someone informed him that he was suffering from eye-trouble. So, he ordered them to bring `Ali in front of him. Then the Prophet (s.a.w.a.) spat in his eyes and his eyes were cured immediately as if he had never any eye-trouble. `Ali said, "We will fight with them (i.e. infidels) till they become like us (i.e. Muslims)." The Prophet (s.a.w.a.) said, "Be patient, till you face them and invite them to Islam and inform them of what Allah has enjoined upon them. By Allah! If a single person embraces Islam at your hands (i.e. through you), that will be better for you than the red camels."
Salama b. Akwa' reported that it was 'Ali whom Allah's Apostle (s.a.w.a.) 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.a.w.a.) 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 (s.a.w.a.) 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 (s.a.w.a.) gave him the standard. Allah granted victory at his hand.
Narrated Sahl: On the day (of the battle) of Khaibar the Prophet (s.a.w.a.) said, "Tomorrow I will give the flag to somebody who will be given victory and who loves Allah and His Apostle and is loved by Allah and His Apostle." So, the people wondered all that night as to who would receive the flag and in the morning everyone hoped that he would be that person. Allah's Messenger (s.a.w.a.) asked, "Where is `Ali (as)?" He was told that `Ali (as) was suffering from eye-trouble, so he applied saliva to his eyes and invoked Allah to cure him. He at once got cured as if he had no ailment. The Prophet (s.a.w.a.) gave him the flag. `Ali (as) said, "Should I fight them till they become like us (i.e. Muslim)?" The Prophet (s.a.w.a.) said, "Go to them patiently and calmly till you enter the land. Then, invite them to Islam, and inform them what is enjoined upon them, for, by Allah, if Allah gives guidance to somebody through you, it is better for you than possessing red camels."
Narrated Sahl bin Sa`d:
Allah's Messenger (s.a.w.a.) said, "Tomorrow I will give the flag to a man with whose leadership Allah will grant (the Muslim) victory." So the people kept on thinking the whole night as to who would be given the flag. The next morning the people went to Allah's Messenger (s.a.w.a.) and every one of them hoped that he would be given the flag. The Prophet (s.a.w.a.) said, "Where is `Ali bin Abi Talib?" The people replied, "He is suffering from eye trouble, O Allah's Messenger (s.a.w.a.)." He said, "Send for him and bring him to me." So when `Ali came, the Prophet (s.a.w.a.) spat in his eyes and invoked good on him, and be became alright as if he had no ailment. The Prophet (s.a.w.a.) then gave him the flag. `Ali said, "O Allah's Messenger (s.a.w.a.)! Shall I fight them (i.e. enemy) till they become like us?" The Prophet (s.a.w.a.) said, "Proceed to them steadily till you approach near to them and then invite them to Islam and inform them of their duties towards Allah which Islam prescribes for them, for by Allah, if one man is guided on the right path (i.e. converted to Islam) through you, it would be better for you than (a great number of) red camels."
Narrated Salama:
`Ali happened to stay behind the Prophet (s.a.w.a.) and (did not join him) during the battle of Khaibar for he was having eye trouble. Then he said, "How could I remain behind Allah's Messenger (s.a.w.a.)?" So `Ali set out following the Prophet (s.a.w.a.) , When it was the eve of the day in the morning of which Allah helped (the Muslims) to conquer it, Allah's Messenger (s.a.w.a.) said, "I will give the flag (to a man), or tomorrow a man whom Allah and His Apostle love will take the flag," or said, "A man who loves Allah and His Apostle; and Allah will grant victory under his leadership." Suddenly came `Ali whom we did not expect. The people said, "This is `Ali." Allah's Messenger (s.a.w.a.) gave him the flag and Allah granted victory under his leadership.
Narrated Salama: `Ali ibn Abi Talib (as) remained behind the Prophet (s.a.w.a.) during the battle of Khaibar as he was suffering from eye trouble. He then said, "(How can) I remain behind the Prophet (s.a.w.a.) ," and followed him. So when he slept on the night of the conquest of Khaibar, the Prophet (s.a.w.a.) 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" While every one of us was hopeful to have the flag, it was said, "Here is `Ali (as)" and the Prophet (s.a.w.a.) gave him the flag and Khaibar was conquered through him.
Narrated Sahl bin Sa`d: On the day of Khaibar, Allah's Messenger (s.a.w.a.) said, "Tomorrow I will give this flag to a man through whose hands Allah will give us victory. He loves Allah and His Apostle, and he is loved by Allah and His Apostle." The people remained that night, wondering as to who would be given it. In the morning the people went to Allah's Messenger (s.a.w.a.) and everyone of them was hopeful to receive it (i.e. the flag). The Prophet said (s), "Where is `Ali bin Abi Talib (as)?" It was said, "He is suffering from eye trouble O Allah's Apostle." He said, "Send for him." `Ali (as) was brought and Allah's Messenger (s.a.w.a.) applied saliva in his eye and invoked good upon him. So `Ali (as) was cured as if he never had any trouble. Then the Prophet (s.a.w.a.) gave him the flag. `Ali (as) said "O Allah's Messenger (s.a.w.a.)! I will fight with them till they become like us." Allah's Messenger (s.a.w.a.) said, "Proceed and do not hurry. When you enter their territory, call them to embrace Islam and inform them of Allah's Rights which they should observe, for by Allah, even if a single man is led on the right path by Allah through you, then that will be better for you than the nice red camels.