The Messenger ( sallal-laahu-alayhi-wasallam ) said: ”
The best of the believers are those with the best manners. The most discerning of them is the one who remembers death the most and makes the best preparation for it. Those are the discerning ones”.
[Declared Hasan’ by Imaam Albaani (rahimahullaah) in As-Saheehah 1384 & also in Irwaa Al-Ghaleel 682]