Mughira b. Shu'ba wrote to Mu'awiya: When the Messenger of Allah (ﷺ) finished the prayer and pronounced salutation he uttered (this supplication):" There is no god but Allah. He is alone, Who has no partner. To Him belongs the sovereignty and to Him praise is due and He is Potent over every. thing. O Allah! no one can withhold what Thou givest, or give what Thou withholdest, and the riches cannot avail a wealthy person with Thee."
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا جَرِيرٌ، عَنْ مَنْصُورٍ، عَنِ الْمُسَيَّبِ بْنِ رَافِعٍ، عَنْ وَرَّادٍ، مَوْلَى الْمُغِيرَةِ بْنِ شُعْبَةَ قَالَ كَتَبَ الْمُغِيرَةُ بْنُ شُعْبَةَ إِلَى مُعَاوِيَةَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ إِذَا فَرَغَ مِنَ الصَّلاَةِ وَسَلَّمَ قَالَ " لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَىْءٍ قَدِيرٌ اللَّهُمَّ لاَ مَانِعَ لِمَا أَعْطَيْتَ وَلاَ مُعْطِيَ لِمَا مَنَعْتَ وَلاَ يَنْفَعُ ذَا الْجَدِّ مِنْكَ الْجَدُّ " .
sunnah.com