'dvitīya catur-vyūha' ei--turīya, viśuddha
vāsudeva-the expansion named Vāsudeva; saṅkarṣaṇa-the expansion named Saṅkarṣaṇa; pradyumna-the expansion named Pradyumna; aniruddha-the expansion named Aniruddha; dvitīya catuḥ-vyūha-the second quadruple expansion; ei-this; turīya-transcendental; viśuddha-free from all material contamination.
Vāsudeva, Saṅkarṣaṇa, Pradyumna and Aniruddha constitute this second quadruple. They are purely transcendental.
Great souls assert that Nārāyaṇa, who is known as Paramātmā, the Supersoul, is beyond material nature, and this is in accordance with the statements of the Vedic literature. Māyāvādīs also agree that Nārāyaṇa can expand Himself in various forms. Śaṅkara says that he does not attempt to argue that portion of the devotees' understanding, but he must protest the idea that Saṅkarṣaṇa is produced from Vāsudeva, Pradyumna is produced from Saṅkarṣaṇa, and Aniruddha is produced from Pradyumna, for if Saṅkarṣaṇa is understood to represent the living entities created from the body of Vāsudeva, the living entities would have to be noneternal. The living entities are supposed to be freed from material contamination by engaging in prolonged temple worship of the Supreme Personality of Godhead, reading Vedic literature and performing yoga and pious activities to attain the Supreme Lord. But if the living entities had been created from material nature at a certain point, they would be noneternal and would have no chance to be liberated and associate with the Supreme Personality of Godhead. When a cause is nullified, its results are nullified. In the second chapter of the Vedānta-sūtra's second khaṇḍa, Ācārya Vedavyāsa has also refuted the conception that the living beings were ever born (nātmā śruter nityatvāc ca tābhyaḥ). Because there is no creation for the living entities, they must be eternal.