Sanskrit: अहिंसा | a-hiṃsā
(non-violence) / also less commonly found as “ahinsa”
The first and often most recognized of the yamas (restraints) as found in the Yoga Sutra is Ahisma. Translating to “non-violence”, Ahisma calls on us to live in a non-harmful manner. Be this through your thoughts, speech, or action, the purpose of Ahisma is not directed towards only other humans, rather all living beings – including ourselves. Here is a quick and well explained breakdown from Kino Yoga
To show the importance of Ahsima, lets look at a text from The Anushasana Parva:
अहिंसा परमॊ धर्मः तथाहिंसा परॊ दमः।
अहिंसा परमं दानम् अहिंसा परमस तपः।
अहिंसा परमॊ यज्ञः तथाहिस्मा परं बलम्।
अहिंसा परमं मित्रम् अहिंसा परमं सुखम्।
अहिंसा परमं सत्यम् अहिंसा परमं श्रुतम्॥
Which translates literally to:
Ahimsa is the highest Dharma, Ahimsa is the highest self-control,
Ahimsa is the greatest gift, Ahimsa is the best practice,
Ahimsa is the highest sacrifice, Ahimsa is the finest strength,
Ahimsa is the greatest friend, Ahimsa is the greatest happiness,
Ahimsa is the highest truth, and Ahimsa is the greatest teaching.
Ahisma is practiced in many other religions and capacities also. Hinduism, Jainism, Sikhism, and Buddhism all consider Ahsima as one of the cardinal values.
The name Ahisma is rooted in hims… meaning to strike > hiṃsā meaning to injure or harm > therefore a-hiṃsā is the contrary – a state of non-violence and/or non-harm.