do no harm
Verb
Meaning
do no harm (third-person singular simple present does no harm, present participle doing no harm, simple past did no harm, past participle done no harm)
(ethics, medicine) To perform no actions which will be injurious or in any way unfavorable to another person, regardless of whether one does anything of positive benefit for that other person.
Examples
Make a habit of two things: to help; or at least to do no harm.
Perhaps it is impossible for a person who does no good to do no harm.
The law of causality, I believe, like much that passes muster among philosophers, is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm.
If you can do no good, at least do no harm.
The gardener's feet do no harm to the garden.
White ants can do no harm to a stone.