Bismillaah:

Anas ibn Malik رضي الله عنه said:

The blessed Prophet صلى الله عليه وسلم said:

'' Remember death in your prayer. Verily , when a person remembers death in his prayer, he is more likely to perfect his prayer. Pray the prayer of a man who does not expect to pray another prayer. And beware of every matter that would require an apology.''

Takhreej:

{ Imam adh Daylaami in his Musnad and graded as Hasan by Shaykh al Albaani رحمه الله }

Shaykh Abu Abdullah Al Libani commented:

'' Remembering death maintains for a person a balance view of life. He would not go to extremes of despair in the face of afflictions, nor would he go to the extreme of arrogance and carelessness when favored by an easy life. Furthermore, when one remembers death while performing an act of worship, he would more likely to perfect that act.''

{ Silsilah Ahadeeth As Saheehah #2839 }

*** And Allaah عزوجل knows best ***