I am pleased with Allah as my Lord, with Islam as my religion, and with Muhammad — Evening Adhkar
رَضِيتُ بِاللَّهِ رَبًّا وَبِالْإِسْلَامِ دِينًا وَبِمُحَمَّدٍ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ نَبِيًّا
Transliteration: Radheetu billaahi rabban wa bil-islaami deenan wa bi-Muhammadin sallallaahu 'alayhi wa sallama nabiyyan
Translation: I am pleased with Allah as my Lord, with Islam as my religion, and with Muhammad (peace be upon him) as my Prophet.
Repeat: 3 times
Reference: Abu Dawud 4:318, Tirmidhi 5:465