The Srimad Bhagavatam has a version of this story, except Vishnu deceives him in a special way: as opposed to turning into Mohini and attracting him, he turns into a younger pupil and charms him along with his words: KSHAM is considered a universal beej mantra which might be chanted https://chancextstx.digiblogbox.com/61992127/a-simple-key-for-hanuman-unveiled