The Prophet—may Allah bless him and grant him peace—said: “Muslims must abide by their stipulations, except for a stipulation that makes lawful what is forbidden or forbids what is lawful.” Reported by the compilers of the Sunan1.

340—Another is when one party suffers a price disadvantage beyond customary bounds, whether through sham bidding, intercepting incoming merchants, or some other means2.

341—Another is the right to cancel for deceptive misrepresentation: when the seller creates a deceptive appearance that increases the price, such as by retaining milk in the udder of livestock.

He—may Allah bless him and grant him peace—said: “Do not retain milk in the udders of camels and sheep. Whoever subsequently purchases one may, after milking it, choose whichever of two options he deems better: if he wishes, he may keep it; and if he wishes, he may return it together with a sāʿ of dates.” Agreed upon. Another wording states: “He has the right to choose for three days”3.

342—If a buyer purchases a defective item without knowing of its defect, he may choose between returning it