مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4115
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah said: I heard The Messenger of Allah (ﷺ) say: "The most evil of people are those upon whom the Hour will come when they are still alive, and those who take graves as places of worship."
Musnad Ahmad 4143Its isnad is hasan]