Viśvarūpa continued: O Indra, this mystic armor related to Lord Nārāyaṇa has been described by me to you. By putting on this protective covering, you will certainly be able to conquer the leaders of the demons.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
मघवन्निदमाख्यातं वर्म नारायणात्मकम् । विजेष्यस्यञ्जसा येन दंशितोऽसुरयूथपान्
maghavannidamākhyātaṃ varma nārāyaṇātmakam | vijeṣyasyañjasā yena daṃśito'surayūthapān
SB 6.8.35