Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: The Muslims would not look at Abu Sufyan (may Allah be pleased with him) nor speak with him, so he said: O Messenger of Allah, there are three things I wish to give you: I have the most beautiful and most handsome woman of the Arabs, Umm Habibah; I will marry her to you. He (peace and blessings be upon him) said: "Yes." He said: And make Mu'awiyah your scribe, keeping him before you. He (peace and blessings be upon him) said: "Yes." He said: And appoint me to fight the disbelievers just as I used to fight the Muslims. He (peace and blessings be upon him) said: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12830