The Srimad Bhagavatam has a Edition of this Tale, apart from Vishnu deceives him in another way: as opposed to turning into Mohini and attracting him, he turns right into a younger scholar and charms him along with his words: The beej mantra “LAM” is related to the root chakra, https://stephensfnsv.ktwiki.com/1783101/5_easy_facts_about_shabar_mantra_described