yad ahadhyatmikam param
yogam tenaiva purusam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Thus the best amongst human beings, Maharaja Prthu, followed that path of spiritual advancement which was advised by Sanat-kumara. That is to say, he worshiped the Supreme Personality of Godhead, Krsna.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In this verse it is clearly said that Maharaja Prthu, practicing the pranayama-yoga system, engaged in the service of the Supreme Personality of Godhead as advised by the saint Sanat-kumara. In this verse the words purusam abhajat purusarsabhah are significant. Purusarsabha refers to Maharaja Prthu, the best amongst human beings, and purusam refers to the Supreme Personality of Godhead. The conclusion is that the best man amongst all men engages in the service of the Supreme Person. One purusa is worshipable, and the other purusa is the worshiper. When the purusa who worships, the living entity, thinks of becoming one with the Supreme Person, he simply becomes bewildered and falls into the darkness of ignorance. As stated by Lord Krsna in Bhagavad-gita (2.12), all living entities assembled in the battlefield, as well as Krsna Himself, were also present in the past as individuals and would continue to be present in the future as individuals also. Therefore the two purusas, the living entity and the Supreme Personality of Godhead, never lose their respective identities.
Actually, one who is self-realized engages himself in the service of the Lord perpetually, both in this life and in the next. Indeed, for devotees there is no difference between this life and the next. In this life a neophyte devotee is trained to serve the Supreme Personality of Godhead, and in the next life he approaches that Supreme Person in Vaikuntha and renders the same devotional service. Even for the neophyte devotee, devotional service is considered brahma-bhuyaya kalpate. Devotional service to the Lord is never considered a material activity. Since he is acting on the brahma-bhuta platform, a devotee is already liberated. He therefore has no need to practice any other type of yoga in order to approach the brahma-bhuta stage. If the devotee adheres strictly to the orders of the spiritual master, follows the rules and regulations and chants the Hare Krsna mantra, it should be concluded that he is already at the brahma-bhuta stage, as confirmed in Bhagavad-gita (14.26):
mam ca yo ’vyabhicarena
sa gunan samatityaitan
“One who is engaged in full devotional service, unfailing in all circumstances, at once transcends the modes of material nature and thus comes to the level of Brahman.”