Visvarupa heard the Narayana-kavaca from Vishnu in His Hayagriva incarnation and described it later to Indra: "This prayer constitutes subtle knowledge transcendentally connected with Narayana. One who employs this prayer is never disturbed or put in danger by the government, by plunderers, by evil demons or by any type of disease."

(Srimad-Bhagavatam 6.8.38)