مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3842
Musnad of Abdullah bin Mas'ood
It was narrated that Abu Wa'il said: 'Abdullah (رضي الله عنه) said: I heard the Messenger of Allah (ﷺ) say: “Whoever ascribes a rival to Allah, Allah will put him in Hell.” And he ('Abdullah) said: And there is something else I say that I did not hear from him: whoever dies not ascribing any rival to Allah, Allah will admit him to Paradise. And these prayers are expiation for whatever (sins) come in between, so long as killing (murder) is avoided.
Musnad Ahmad 3865Saheeh and its isnad is hasan]