Riyad us Saliheen: Hadith 1106

The Messenger of Allah (ﷺ) used to recite during the two Rak'ah of Fajr prayer: "Say (O Muslims): We believe in Allah and that which has been sent down to us..." (2:136) which is in Surat Al-Baqarah in the first Rak'ah and the Verse: "We believe in Allah, and bear witness that we are Muslims (i.e., we submit to Allah." (3:52) in the second Rak'ah.

According to another narration, he (ﷺ) recited from Surat Al-'Imran the Verses: "Come to a word which is just between us and you..." (3:64).

[Muslim].