Srimad Bhagavatam Canto 01, Chapter 04, Text 27

SB 1.4.27

natiprasidad-dhrdayah
sarasvatyas tate sucau
vitarkayan vivikta-stha
idam covaca dharma-vit
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Thus the sage, being dissatisfied at heart, at once began to reflect, because he knew the essence of religion, and he said within himself:
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The sage began to search out the cause of not being satisfied at heart. Perfection is never attained until one is satisfied at heart. This satisfaction of heart has to be searched out beyond matter.
Srimad Bhagavatam Canto 01, Chapter 04, Text 26
Srimad Bhagavatam Canto 01, Chapter 04, Text 28-29