Sunan Abi Dawud Book 2, Hadith 443
we used to offer supererogatory prayers and recite supplications while we were standing, and would glorify Allah while bowing and prostrating.
A man came to the Prophet (ﷺ) and said: I cannot memorise anything from the Qur'an: so teach me something which is sufficient for me. He said: Say Glory be to Allah, and praise be to Allah, and there is no god but Allah, and Allah is most great, and there is no might and no strength but in Allah.
:He said: Messenger of Allah, this is for Allah, but what is for me? He said: Say: O Allah have mercy on me, and sustain me, and keep me well, and guide me. When he stood up, he made a sign with his hand (indicating that he had earned a lot).
The Messenger of Allah (ﷺ) said: He filed up his hand with virtues.
Al-Hasan (al-Basri) would recite fatihat al-kitab in the noon and afternoon prayers while he led in prayer or he was behind the imam and would glorify Allah, and would repeatedly say: “Allah is most great” and “ There is no god but Allah” (i.e takbir and tahlil) equal to the amount one recites al-Qaf (Surah 50) and al-Dhariyat(surah 51).