Durgama, the weeping eyes and the goddess of greens
The demon Durgama wins all the Vedas from Brahma; worship stops, rain stops, and a hundred years of drought follow. The goddess appears with countless eyes and weeps for nine days until the rivers fill, feeds the world from her own body as Shakambhari, then kills Durgama and takes his name: Durga.
Durgama, son of Ruru, works out that the strength of the gods is the Vedas. He goes to the Himalaya and lives on air for a thousand years, and Brahma comes on his swan and offers a boon. All the Vedas, he asks, and the strength to beat the gods. From that day the brahmins forget the Vedas; bathing, evening prayer, fire offerings and sacrifice all stop, the gods weaken and Durgama besieges their city. No rain falls for a hundred years. The brahmins go to the mountains and pray, and the goddess appears covered with eyes, and weeps from all of them for nine days and nights, until the water runs in rivers. She holds greens and roots and fruit and feeds the world from her own body. Then she fights Durgama, the Shaktis pouring out of her, kills him, and gives the Vedas back: these are parts of my body, keep them carefully. My name is Durga, because I killed Durgama.
In the older Devi Mahatmya the story is a promise. After Shumbha and Nishumbha are dead and the gods praise her as Narayani, the goddess tells them the births still to come: when rain fails for a hundred years she will be born not of a womb, look at the sages with a hundred eyes and be called Shatakshi; she will feed the world with life-sustaining plants from her own body and be called Shakambhari; and she will kill the great demon Durgama, and be called Durga. Her temples as Shakambhari stand at Saharanpur in Uttar Pradesh, by Sambhar Lake in Rajasthan and at Badami.