مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2255
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) prayed two rak'ahs when travelling and four rak'ahs when not travelling. Ibn 'Abbas (رضي الله عنه) said: Whoever prays four rak'ahs when travelling is like the one who prays two rak'ahs when not travelling. Ibn 'Abbas (رضي الله عنه) said: Prayer was not shortened except once, when the Messenger of Allah (ﷺ) prayed two rak'ahs, and the people prayed one rak'ah each [in two groups, as in the fear prayer].
Musnad Ahmad 2262Its isnad is da'eef because Humaid bin Ali is da'eef]