مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2640
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that ‘Ikrimah said: I prayed behind an old man in Makkah and he said twenty two takbeers in Zuhr prayer. I came to Ibn 'Abbas and said: I prayed behind a foolish old man, he said takbeer twenty two times in Zuhr prayer. He said: May your mother be bereft of you! That is the Sunnah of Abul-Qasim (ﷺ).
Musnad Ahmad 2656Its isnad is saheeh, al-Bukhari (788)]