It is narrated on the authority of 'Abbas b. 'Abdul-Muttalib that he heard the Messenger of Allah (ﷺ) saying: He has found the taste of faith (iman) who is content with Allah as his Lord, with Islam as his religion (code of life) and with Muhammad (ﷺ) as his Prophet.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ يَحْيَى بْنِ أَبِي عُمَرَ الْمَكِّيُّ، وَبِشْرُ بْنُ الْحَكَمِ، قَالاَ حَدَّثَنَا عَبْدُ الْعَزِيزِ، - وَهُوَ ابْنُ مُحَمَّدٍ - الدَّرَاوَرْدِيُّ عَنْ يَزِيدَ بْنِ الْهَادِ، عَنْ مُحَمَّدِ بْنِ إِبْرَاهِيمَ، عَنْ عَامِرِ بْنِ سَعْدٍ، عَنِ الْعَبَّاسِ بْنِ عَبْدِ الْمُطَّلِبِ، أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " ذَاقَ طَعْمَ الإِيمَانِ مَنْ رَضِيَ بِاللَّهِ رَبًّا وَبِالإِسْلاَمِ دِينًا وَبِمُحَمَّدٍ رَسُولاً "
sunnah.com