Musnad Abu Ya'la al-Mawsili 159:134

Amr ibn Muhammad narrated to us, Yazid ibn Harun narrated to us, from Muhammad ibn Amr, from Ismail ibn Umayyah, from Ata ibn Yasar, from Abu Hurairah: That the Messenger of Allah (ﷺ) used to prostrate during "Iqra' bismi Rabbika" (Surah Al-Alaq) and "Idha as-sama'u inshaqqat" (Surah Al-Inshiqaq).