Sunan Abi Dawud Book 2, Hadith 427
As if I am hearing the voice of the prophet (may peace by upon him) who would recite at the morning prayer “Oh, but I call to witness the planets, the stars which rise and set”(surah 81:15-16)
A man of Juhaynah told him that he had heard the Prophet (ﷺ) reciting "When the earth is shaken" (Surah 99) in both rak'ahs of the morning prayer. But I do not know whether he had forgotten, or whether he recited it on purpose.
we were commanded to recite Fatihat al-kitab and whatever was convenient (from the Qur’an during the prayer).