Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 38
Sanskrit:
इमां विद्यां पुरा कश्चित्कौशिको धारयन् द्विज: ।योगधारणया स्वाङ्गं जहौ स मरुधन्वनि ॥ ३८ ॥
ITRANS:
imāṁ vidyāṁ purā kaścitkauśiko dhārayan dvijaḥyoga-dhāraṇayā svāṅgaṁjahau sa maru-dhanvani
Translation:
O King of heaven, a brāhmaṇa named Kauśika formerly used this armor when he purposely gave up his body in the desert by mystic power.