What is Ahimsa?
अहिंसा
A (no) + Himsa (injury)
Ahiṃsā is the first and most important of Patanjali’s yamas, meaning non-harming or non-violence:
II.30 ahiṁsā-satyāsteya-bramacaryāparigrajā yamaḥ
Ahiṁsā, nonviolence; satyā, truthfulness; āsteya, refraining from stealing; brahmacaryā, celibacy; aparigrāhah, refrainment from acquisition or coveting; yamaḥ, the abstentions
The yamas are instructions for how one should treat other beings, otherwise known as ‘rules and observances’. Evidence can also be found of these in previous texts such as the Mahābhārata and the Ācārāṅga Sūtra, the earliest surviving Jain text (c.350 BCE).