Dasakam: 016 -- Shlokam: 03
दैत्यं सहस्रकवचं कवचै: परीतं
साहस्रवत्सरतपस्समराभिलव्यै: ।
पर्यायनिर्मिततपस्समरौ भवन्तौ
शिष्टैककङ्कटममुं न्यहतां सलीलम् ॥३॥
daityaM sahasrakavachaM kavachaiH pariitaM
saahasravatsaratapassamaraabhilavyaiH |
paryaayanirmitatapassamarau bhavantau
shiShTaikakankaTamamuM nyahataaM saliilam || 3
Karna was an Asura named SAHASRA KAVACHA.he was so named because he was born protectedby a thousand coats of armor (Kavacha).The specialty of these 'Kavachas' was that no one could break them without performing thousand years of penance and at the same time fighting with him simultaneously for the same thousand years. This explains the secret of the birth of the twin brothers, who were for all purposes considered as 'one’, even though possessing two bodies. Nara and Narayana, in turn, did "Tapas" (penance)as well as the fighting for thousand years and finally killed the Asura, Sahasra Kavacha