Srimad Bhagavatam Canto 12, Chapter 03, Text 49

SB 12.3.49

tasmat sarvatmana rajan
 hrdi-stham kuru kesavam
mriyamano hy avahitas
 tato yasi param gatim
 
Translation: 
 
Therefore, O King, endeavor with all your might to fix the Supreme Lord Kesava within your heart. Maintain this concentration upon the Lord, and at the time of death you will certainly attain the supreme destination.
 
Purport: 
 
Although the Supreme Lord is always in the heart of every living being, the words hrdi-stham kuru kesavam indicate that one should endeavor to realize the Lord’s presence there and maintain this awareness at every moment. Pariksit Maharaja is about to give up this world and is receiving final instructions from his spiritual master, Sukadeva Gosvami. In the context of the King’s imminent departure, this verse has special significance.
Srimad Bhagavatam Canto 12, Chapter 03, Text 48
Srimad Bhagavatam Canto 12, Chapter 03, Text 50