Musnad Ahmad 626:6

'Abd al-Razzaq and Ibn Bakr narrated to us, they said: Ibn Jurayj informed us. And Rawh narrated to us, Ibn Jurayj narrated to us, 'Abdah ibn Abi Lubabah informed me that Warrad, the freed slave of al-Mughirah ibn Shu'bah, informed him: That al-Mughirah ibn Shu'bah wrote to Mu'awiyah, and Warrad wrote the letter for him: "I heard the Prophet, peace and blessings of Allah be upon him, saying when he would finish the prayer: 'There is no god but Allah alone, He has no partner. To Him belongs the dominion, and to Him belongs the praise. O Allah, there is no preventer for what You have given, and no giver for what You have prevented, and the wealth of the wealthy will not benefit him against You.'" Warrad said: "Then I arrived to Mu'awiyah after that, and I heard him on the pulpit commanding the people with that statement and teaching it to them."