What Sikhism says about doing no harm
Someone looking for a Sikh version of non-violence will find something more divided than they expect. The tradition is firm about the harm done by tempers, tongues and dishonest earnings. It is not pacifist. Where peaceful means have failed, the same tradition holds armed resistance to tyranny to be right. The concepts below run in that order: the harm to avoid, then the exception, then the goal the exception is supposed to serve.
Nirvair - Without Enmity
God is described as having no enemies at all. If that is the nature of the Divine, then carrying an enemy marks a gap in the person carrying one.
Guru Granth Sahib, Ang 1299
Krodh - Anger
Anger is one of the five thieves. The library allows indignation at injustice, but says uncontrolled anger consumes the person who harbours it.
Guru Granth Sahib
Nindya - Slander
Speaking ill of someone is counted as harm to the speaker as well as the subject. True remarks about another person's faults are still generally to be left unsaid.
Guru Granth Sahib
Truthful Speech
Truth is required, and so is the manner of it. Speech that wounds more than it needs to is a fault even when it is accurate.
Guru Granth Sahib
Rejection of Exploitation
Money made by exploiting or defrauding people cannot be cleaned up by prayer. The livelihood has to be innocent, not just the ritual.
Guru Granth Sahib, Ang 472
Ethical Investment
A modern application of that rule rather than a scripture verse: do not place money where it profits from harm to workers or to the land. The library records it as a derived principle.
Contemporary Interpretation
Protection of the Oppressed
Strength carries a duty to shield the weak. The Khalsa was formed partly for this, which is why the martial side of the tradition is described as defensive.
Bachitar Natak
Resistance to Tyranny
This is where Sikhism parts company with non-violence as an absolute. When peaceful means have failed, armed resistance against oppression is held to be righteous.
Zafarnama
Peace as Goal
The exception is not an appetite. War is never glorified in the library's account; it is accepted as sometimes the way to end greater violence, and peace stays the aim.
Guru Granth Sahib
So the honest answer has two halves. Sikh teaching is strict about everyday harm, and it refuses to promise that harm can always be avoided by standing back. What it asks instead is that force be defensive, late, and pointed at ending violence rather than at winning. A reader who wants a single clean rule will not find one here.