'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.
"Although the Supreme Personality of Godhead has nothing to do, He nevertheless acts; although He is always unborn, He nevertheless takes birth; although He is time, fearful to everyone, He flees Mathurā in fear of His enemy to take shelter in a fort; and although He is self-sufficient, He marries 16,000 women. These pastimes seem like bewildering contradictions, even to the most intelligent." Had these activities of the Lord not been a reality, sages would not have been puzzled by them. Therefore such activities should never be considered imaginary. Whenever the Lord desires, His inconceivable energy (yogamāyā) serves Him in creating and performing such pastimes.