Jain saints boil water mainly to reduce harm to the tiniest living beings in water. The principle of ahimsa (non-violence) leads Jains to try to minimize killing or injuring even microorganisms. Boiling (often followed by filtration) kills or disables many micro-life forms, so when they drink, they are not unintentionally harming those beings. Some monastic rules also emphasize drinking boiled and filtered water, especially for renunciants, and there are period-based practices (e.g., during certain vows or seasons) about when and how this is done. Different Jain communities may have slightly different rules about timing and handling, but the core idea is to practice non-violence and care for all life, even at the microscopic level.

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