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.