Prabhupada's lecture - Śrīmad-Bhāgavatam 1.5.11 - New Vrindaban, June 10, 1969
So Parīkṣit Mahārāja said there are three stages. Bhavauṣadhāc chrotra-mano... In three ways it is so nice, palatable. So why one should be aloof from this chanting? Ka uttama-śloka-guṇānu... Who can be aloof from this chanting or hearing about the activities, pastimes of the uttama-śloka, Supreme Personality of Godhead? Vinā paśughnāt [SB 10.1.4]. The only person: who is paśughnāt. Paśughnāt means animal-killer. A person who is animal-killer, he'll not be interested. The animal-killer, you can, I mean to say, analyze the meaning in two ways. Animal killer means not exactly those who are butchers, or ordinary man who kills animal and eat. But even a person who does not take care of his self-realization, he is also animal-killer. He is killing himself. He is also animal-killer. Because this life is meant for self-realization, but he's not taking interest in self-realization.
He is taking pleasure only just like animal. So I am also an animal. I am killing myself. If I don't take interest in self-realization and if I glide down again into the cycle of birth and death, then I am killing myself. Suiciding. That is our willing, killing ourself willingly. If I know that "If I do this, I will be punished like this," and if I still do this, then I am killing myself.