The Devi Mahatmyam is a derived from the Markandeya Purana (chapters 81-93), one of the early Sanskrit Puranas, containing stories told by the sage Markandeya to Jaimini and his students. The story of Sumbha and Nisumbha is featured in the fifth chapter of the Devi Mahatmyam.
Shumbha and Nishumbha, the two Asura brothers performed severe penance to obtain a boon from Lord Brahma that they cannot be killed by any male-human,Deva or animal alike. Emboldened and empowered by the boon, the two brothers sought to conquer the Three Worlds. The Devas soon discovered that they were no match for the rampaging Asura army. They narrowly escaped and prayed together for the Maha Devi to save them for certain defeat. Maa Parvati, the embodiment of Maa Adya Sakti or Mahamaya, took pity on the plight of the Devas and created the beautiful Goddess Kaushiki and herself took the form of Maa Kali. Seeing the beautiful Devi, Shumbha and Nishumbha offered to marry her. The Devi replied she can only marry the one who defeats her in battle. Hearing this, the two Asuras sent their most fearsome generals one by one to defeat the Devi, Chanda and Munda came, Dhumralochan came and finally Raktabeej. But Maa Kali beheaded every one of them. Finally it was the turn of Shumbha and Nishumbha. They fought with all their might, but were no match for Maa Kali, who was the embodiment of death. As one by one she severed the heads of the mighty Asuras, the Devas finally heaved a sigh of relief as peace returned both on earth and the heavenly abode of the Gods.
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