Does an invalid condition attached to a sale automatically void the entire contract?
Chapter on the Option of the Two Parties in Sale
Al-Mughni
Book of Sales
Primary text
There are two narrations regarding whether an invalid condition voids the sale. The first narration, which is the position of Al-Shafi'i, states that the contract is voided because a contract accompanied by an invalid condition is void, similar to *nikah al-shiğar* (marriage for the exchange of brides) or *muhallil* marriage. Moreover, the vendor agreed to relinquish the item for this price only with the option to reclaim it, and the buyer agreed to the price with the option to rescind. Validating it without the condition removes the ownership of both parties against their will. Additionally, the condition takes a portion of the price; removing it necessitates returning an unknown amount of the price, rendering the price itself unknown and thus voiding the contract.
Supporting text
The second narration states that the contract is not voided by the invalid condition, which is the opinion of Ibn Abi Laila, citing the Hadith of Barirah. This is because the contract's pillars were completed, and the condition is extraneous; if the condition becomes invalid and ceases, the contract remains valid with its pillars, as if the condition was never stipulated.