It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) used to recite «﴿قُولُواآمَنَّابِاللّٰهِوَمَاأُنْزِلَإِلَيْنَاوَمَاأُنْزِلَإِلَىإِبْرَاهِيمَ﴾ [البقرة : 136]» in the first rak'ah of Fajr and «﴿آمَنَّابِاللّٰهِوَاشْهَدْبِأَنَّامُسْلِمُونَ﴾ [آل عمران : 52]» in the second rak'ah.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 2045