مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2064
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn ‘Abbas said: The Messenger of Allah (ﷺ) said: “I was commanded to pray two rak'ahs of Duha and Witr, but that is not obligatory for you."
Musnad Ahmad 2065Its isnad is da’eef]