This prayer, Nārāyaṇa-kavaca, constitutes subtle knowledge transcendentally connected with Nārāyaṇa. 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 Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
न कुतश्चिद्भयं तस्य विद्यां धारयतो भवेत् । राजदस्युग्रहादिभ्यो व्याध्यादिभ्यश्च कर्हिचित्
na kutaścidbhayaṃ tasya vidyāṃ dhārayato bhavet | rājadasyugrahādibhyo vyādhyādibhyaśca karhicit
SB 6.8.37