مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3621
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah bin Mas'ood (رضي الله عنه) said: When I tell you of a hadeeth from the Messenger of Allah (ﷺ), then think of the Messenger of Allah (ﷺ) as being the best, the most guided and the most pious.
Musnad Ahmad 3645A saheeh hadeeth; this is a da’eef isnad]