Is the option nullified if the parties agree to waive the option (Takhayur) either before or after the contract?
Chapter on the Option of the Two Parties in Sale
Al-Mughni
Book of Sales
Primary text
The apparent statement of Al-Khiraqi indicates that the option extends until separation and is not nullified by waiving it before or after the contract; this is one narration from Imam Ahmad, as most narrations from the Prophet (PBUH) mention the option 'until they separate' without restriction or specification. The second narration suggests the option is nullified by waiving it, a view chosen by Al-Sharif bin Abi Musa, and it is the Madhhab of Imam al-Shafi'i, considered stronger based on the Hadith regarding Ibn Umar stating, 'If one of them chooses his counterpart, and they contract upon that, the sale is obligated (wajaba).' Waiving the option at the beginning means saying, 'I sell to you and there is no option between us,' and the other accepts. Waiving it afterward means one says after the contract, 'I choose to uphold the contract' or 'I relinquish my option.' If both choose to enforce it, the contract is binding on both. If only one chooses it, it is binding only upon him, similar to contractual option shared by both, where one relinquishes it.
Supporting text
The view of the Shafi'is regarding waiving the option at the beginning of the contract suggests two possibilities; the more apparent one is that the option is not cut short because it is relinquishing a right before its cause occurs, which is invalid, like the option of pre-emption. Based on this, there are two opinions on whether the contract is voided by this condition, depending on rulings on invalid conditions. Furthermore, if one says to the other, 'Choose,' and the other says nothing, the silent one retains his option, as he did not do anything to invalidate it.