Often the Messenger of Allah ﷺ would recite in the two rakahs of the dawn prayer the verse "We have believed in Allah and what has been revealed to us". Ati said, this was in the first rakah, and in the second rakah he would recite "We have believed in Allah, and bear witness that we are Muslims".
حدثنا أحمد بن يونس حدثنا زهير حدثنا عثمان بن حكيم أخبرني سعيد بن يسار
أن كثيرا مما كان يقرأ رسول الله ﷺ في ركعتي الفجر ب {آمنا بالله وما أنزل إلينا} هذه الآية قال هذه في الركعة الأولى وفي الركعة الآخرة ب {آمنا بالله واشهد بأنا مسلمون}
Muslim narrated it in the Book of the Prayer of Travelers, in the chapter on the recommendation of the two rakahs of the sunnah of Fajr and the encouragement to perform them, and so on, hadith no. 727, from the hadith of Uthman bin Hakeem, through this same chain.