In Hinduism, sarsapa or sarshapa is the Sanskrit word for mustard. It is used as an oblation in homa and Havana (yajnas) to propitiate devatas (deities). Sarsapa is also used for purification, with recitation of the relevant mantra in various samskaras prescribed for Hindus.
The term sarsapa is also used in general conversation as a comparative term for infinitesimally small items, the other extreme being the mountain. As a famous Hindi proverb goes, a bad man, it is said, recognizes the mistakes of others even if they are of the size of a mustard grain and ignores his own mistakes of a mountainous size.
Sarsapa oil is used for preparing food, particularly for frying vegetables and other eatables. Black mustard is used to add taste to soups and other spicy food preparations. Sarsapa seeds spluttered in oil are a good digestive agent. Even diabetic patients can add sarsapa seeds to the food, but without spluttering them in oil. In winter, the leaves of sarsapa are consumed in North India as sarson-ka-sag.
Black sarsapa seeds are used as garnish in almost all parts of India.
Sarsapa oil is also good for body massage. The extracts of sarshapa oil mixed with other herbs are used for medicinal bathing purposes. The paste of white sarsapa boiled in milk, cooled and applied to the face brightens the facial skin. In Ayurveda, it is used for medicinal purposes.