Musannaf Ibn Abi Shayba 3:84

Abu Bakr narrated to us, he said: Abd al-Salam ibn Harb narrated to us, from Sa'id, from Abu Ma'shar, from Ibrahim, who said: If he says "Subhan Allah" (Glory be to Allah), or "Allahu Akbar" (Allah is the Greatest), or "La ilaha illa Allah" (There is no god but Allah), it suffices him in the opening (of the prayer). And he performs the two prostrations of forgetfulness.