Story of origin of sword in Hinduism is mentioned in the
Puranas. Devas, or demigods, were constantly harassed by the demons (asuras).
Fed up with this constant fighting, Devas asked Brahma for a solution.
To help the Devas, Brahma along with numerous other rishis
performed a yajna in the Himalayas.
During the course of the yajna, a dreadful creature appeared
from the havan kund (sacrificial fire). It had a thin and skinny body, which
was deep blue in color. Its teeth were sharp and ugly looking. Although thin,
it showed great strength and power.
When it moved around, the earth started trembling, huge
waves appeared in the oceans, there were huge winds, trees started falling and
meteors appeared in the sky.
Brahma then asked the powerful being to take the form of a
sword and protect Dharma.