مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1861
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Moosa bin Salamah said: We were with Ibn ‘Abbas in Makkah and I said: When we are with you, we pray four (rak"ahs) and when we go back to our lodgings, we pray two rak"ahs. He said: That is the Sunnah of Abul-Qasim (عليه السلام).
Musnad Ahmad 1862Hasan (Darussalam) []