The Messenger of Allah said on the Day of Khaybar: I will give this banner tomorrow to a man at whose hands Allah will grant victory. A man who loves Allah and his Messenger, and whom Allah and his Messenger love. So the people spent the night wondering who would it be given to. In the morning, people went to the Messenger of Allah, each hoping that he would be given it. The prophet (PBUH) said: Where is Ali ibin Abi Talib? People responded: O Messenger of Allah, there is something wrong with his eyes. So they sent for him, and he was brought. Then, the Messenger of Allah spat in his eyes and made a supplication for him, so he was healed, as if he had no ailment. So he gave him the banner. Ali said: O Messenger of Allah, shall I fight them until they become like us? So the prophet (PBUH) said: Advance patiently and calmly until you reach their territory, then call upon them to accept Islam and inform them about their duties according to Allah's rights in Islam. For by Allah, if Allah guides even one man through you is better for you than to have red -the most valuable- camels.

Ibn 'Awn said: I wrote to Nafi' asking him about calling to Islam before combat, so he wrote to me that this was at the beginning of Islam. The Prophet of Allah (PBUH) raided Banu Al-Mustaliq while they were unaware and their livestock were drinking water at the watering place, so he killed their fighters and took their women and children right hand possessions, and on that day he captured Juweiriyah, the daughter of Al-Harith [later to be he Prophet's wife]. Nafi' said: 'Abdullah told me about that, and he was in that army.