مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2152
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Jabir said: I heard ash-Sha'bi narrate that Ibn 'Umar and Ibn 'Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) prescribed prayer, two rak'ahs when travelling and it is a complete prayer, and Witr when travelling is Sunnah.
Musnad Ahmad 2156Its isnad is da’eef because of the weakness of Jabir al-Ju'f