Musnad Ahmad 2324

It was narrated that Ibn ‘Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) did not prescribe anything but I learned it, apart from three things. I do not know whether the Messenger of Allah (ﷺ) recited in Zuhr and 'Asr or not. And I do not know how he recited this verse: "Wa qad balaghtu minal kibari ‘utiyya” or “ 'usiyya” (referring to the verse "and I have reached the extreme old age” [Maryam 19:8]). Husain said: And I forgot the third. 'Abdullah said: I heard it all from 'Uthman bin Muhammad.