رَضِيتُ باللَّهِ رَبًّا، وَبِالْإِسْلَامِ دِيناً، وَبِمُحَمَّدٍ صَلَى اللَّهُ عَلِيهِ وَسَلَّمَ نَبِيَّاً. (ثلاثاً)

I am pleased with Allah as a Lord, and Islam as a religion and Muhammad peace be upon to him as a Prophet. (three times)

Abu Dawud 4:318