مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3671
Musnad of Abdullah bin Mas'ood
It was narrated from 'Abdur-Rahman bin ‘Abdullah bin Mas'ood, that his father said: The Messenger of Allah (ﷺ) summoned us and we were forty men. 'Abdullah said: I was one of the last to come to him and he said: "You are on the right path and will prevail, and you will conquer other lands. Whoever among you lives to see that, let him fear Allah, enjoin what is good and forbid what is evil. And whoever tells a lie about me deliberately, let him take his place in Hell.”
Musnad Ahmad 3694its isnad is hasan according to those who regard as saheeh w