Abu Said Sad bin Malik bin Sinan al-Khudri (may Allah be pleased with him) narrated that the Messenger of Allah (peace be upon him) said: "harm (darar) may neither be inflicted nor reciprocated." [Ibn Majah]
This hadith has been adopted into a legal maxim in precisely the same wording as the hadith itself. The ruling it contains subsumes all harmful acts and abusive exploitation of resources, even if by the owner, in a way that manifestly harms others, damages the environment, and violate the limits of moderation. The harm so inflicted must be manifest and exorbitant, which means that negligible harm is usually tolerated, especially when it emanates from the normal exercise of one's rights, say of ownership, but harms another person. The owner's exercise of ownership rights may cause some harm to another person/s, but unless it is manifest and exorbitant, no legal action may be taken. Yet the owner's use of his own property may be captured by the rules of darar if it inflicts harm on others. When the owner builds a structure, for instance, that blocks sunlight from the neighbour's living quarters, when he digs a well so close to the neighbour's house that it weakens or endangers its safety, or when his manner of use pollutes the neighbour's living quarters, and so on, the owner may in all these cases be stopped or ordered to indemnify the harm so inflicted.
The renowned Syrian scholar Mustafa Ahmad al-Zarqa (d. 1999) wrote: "This hadith lays down one of the pillars of the Shariah and provides a basis for prevention of all harmful action. But once committed, harm must be indemnified, be it in financial or in punitive terms, just as it provides support for the promotion and encouragement of its opposite, namely all that which benefit the people and protect them against prejudice must be sought after and secured." Zarqa adds that the hadith-cum-legal maxim subsumes harm inflicted to persons, property, and personal rights, to labour relations, commercial transactions, and the like. The owner of an animal, for instance, is accountable for the damage the animal inflicts on another's person or property, and so is the owner of dangerous weapons and instruments that are not properly guarded or used. An unqualified physician is held responsible for the harm his treatment has inflicted on the patient, and so is a witness who gives erroneous testimony that leads to harming its victim. Market operators and restaurateurs are responsible for keeping the market a safe place for the people, and so are food providers who are responsible for the purity and safety of their supplies. Both the principal actor and one who causes harm indirectly are held responsible, and there are rules that apply to inchoate harm that has begun but that remains incomplete.
"The Middle Path of Moderation in Islam: The Qur'anic Principle of Wasatiyyah (Religion and Global Politics)" - Mohammad Hashim Kamali, pp. 124, 125