Most people are only familiar with the Bhagavad Gita, the conversation Krishna had with Arjuna on the battlefield of Kurukshetra. But this is not the only conversation that Krishna had concerning the proper way to live one's life; there's also the Anu Gita and the Uddhava Gita. The Uddhava Gita is a conversation found in the Srimad Bhagavatam between Krishna and his relative Uddhava, shortly before Krishna departed the earth.
In any case, in one chapter of the Uddhava Gita, Krishna teaches Uddhava the proper way to worship him in idol form, and in particular he says this:
The worshiper should bathe the Deity every day, as opulently as his assets permit, using waters scented with sandalwood, uśīra root, camphor, kuṅkuma and aguru. He should also chant various Vedic hymns, such as the anuvāka known as Svarṇa-gharma, the Mahāpuruṣa-vidyā, the Puruṣa-sūkta and various songs of the Sāma Veda, such as the Rājana and the Rohiṇya.
The Purusha Sukta is a famous hymn to Vishnu from the Rig Veda, but my question is, what is the Mahapurusha Vidya? This book claims that it's just a name for the first verse of the Vishnu Purana. Here is the Vishnu Purana's first verse:
jitaṃ te puṇḍarīkākṣa namas te viśvabhāvana |
namas te 'stu hṛṣīkeśa mahāpuruṣa pūrvaja ||
Victory be to thee, Puńd́aríkáksha; adoration be to thee, Víswabhávana; glory be to thee, Hrishikeśa, Mahápurusha, and Púrvaja.
This verse does refer to the Mahapurusha name of Vishnu. But is the author right that this is the Mahapurusha Vidya? Or does it refer to something else? Are there any other scriptures that use the term "Mahapurusha Vidya"?