مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3767
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah (رضي الله عنه) said: The Messenger of Allah (ﷺ) said: "There will be in charge of your affairs after I am gone men who will extinguish the sunnah and introduce bid'ah (innovation); they will delay the prayer from its proper time.” Ibn Mas'ood (رضي الله عنه) said: O Messenger of Allah, what should I do if I live to see them? He said: "O Ibn Umm 'Abd, there is no obedience to the one who disobeys Allah.” And he said it three times.
Musnad Ahmad 3790Its isnad is hasan according to those who think it is true t