Srimad Bhagavatam Canto 12, Chapter 04, Text 34

SB 12.4.34

yadaivam etena viveka-hetina
 maya-mayahankaranatma-bandhanam
chittvacyutatmanubhavo ’vatisthate
 tam ahur atyantikam anga samplavam
 
Translation: 
 
My dear Pariksit, when the illusory false ego that binds the soul has been cut off with the sword of discriminating knowledge and one has developed realization of Lord Acyuta, the Supreme Soul, this is called the atyantika, or ultimate, annihilation of material existence.
Srimad Bhagavatam Canto 12, Chapter 04, Text 33
Srimad Bhagavatam Canto 12, Chapter 04, Text 35