What is the ruling if a person swears an oath not to buy an item for ten units of currency, and subsequently buys it for that amount or more?
General Chapter
Al-Mughni
Book of Expiations
Primary text
If a person swears an oath not to buy an item for ten, and purchases it for exactly ten or for more than ten, the oath is broken (Hanth). This is because the oath is understood conventionally and implicitly to cover the amount specified and everything above it, similar to an oath where one declares, 'I do not owe you a single grain (Habbah),' under which one is held accountable if they owe more than one grain, and the oath absolves them of the excess above the stated single grain.
Supporting text
The implication of Al-Shafi'i's position suggests that the oath is not broken if the purchase is for more than ten, as the explicit wording does not cover the higher amount.