Prabhupada, SB 1.13.55: [...] The living being, by his desiring to lord it over the material world and declining to cooperate with the Supreme Lord, contacts the sum total of the material world, namely the mahat-tattva, and from the mahat-tattva his false identity with the material world, intelligence, mind and senses is developed.
This covers his pure spiritual identity. By the yogic process, when his pure identity is realized in self-realization, one has to revert to the original position by amalgamating the five gross elements and the subtle elements, mind and intelligence, into the mahat-tattva again. Thus getting freed from the clutches of the mahat-tattva, he has to merge in the existence of the Supersoul.
In other words, he has to realize that qualitatively he is non-different from the Supersoul, and thus he transcends the material sky by his pure identical intelligence and thus becomes engaged in the transcendental loving service of the Lord.
This is the highest perfectional development of spiritual identity, which was attained by Dhrtarastra by the grace of Vidura and the Lord. The Lord’s mercy was bestowed upon him by his personal contact with Vidura, and when he was actually practicing the instructions of Vidura, the Lord helped him to attain the highest perfectional stage.
A pure devotee of the Lord does not live on any planet of the material sky, nor does he feel any contact with material elements. His so-called material body does not exist, being surcharged with the spiritual current of the Lord’s identical interest, and thus he is permanently freed from all contaminations of the sum total of the mahat-tattva.
He is always in the spiritual sky, which he attains by being transcendental to the sevenfold material covering by the effect of his devotional service. The conditioned souls are within the coverings, whereas the liberated soul is far beyond the cover. Full Chapter