مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3265
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn ‘Abbas (رضي الله عنه) and Sa'eed bin jubair that The Messenger of Allah (ﷺ) put two prayers together when travelling.
Musnad Ahmad 3288Saheeh]