An essential practice in Yoga is ahimsa. The word himsa in Sanskrit means to do harm, and the "a" in front indicates negation, so ahimsa means "not-harming," or "non-harming."
This non-harming is applied to action, speech and thought. So, we strive to act, speak and even think in ways that do no harm.
Looked at from a slightly different perspective, practicing ahimsa means acting, speaking, and thinking lovingly.
This might seem like a big order. But as we grow in Yoga, we gain the capacity to be more and more loving.