Musnad Ahmad 626:99

Ali ibn Asim narrated to us, al-Mughirah narrated to us, Amir informed us, from Warrad, the scribe of al-Mughirah ibn Shu'bah, who said: Mu'awiyah wrote to al-Mughirah ibn Shu'bah: "Write to me what you heard from the Messenger of Allah, may Allah bless him and grant him peace." Al-Mughirah called me and said: "Write to him that I heard the Messenger of Allah, may Allah bless him and grant him peace, when he finished the prayer, say: 'There is no god but Allah alone, He has no partner; to Him belongs the dominion, and to Him belongs the praise, and He is capable of all things. O Allah, there is no preventer of what You have given, and no giver of what You have prevented, and the wealth of the wealthy will not benefit them against You.'" And I heard him forbid: "He-said-and-she-said (gossip), excessive questioning, wasting wealth, the burying of daughters alive, disobedience to mothers, and withholding (what is due) and demanding (what is not due)."