When two persons enter into a transac. tion, each one of them has the right to annul it so long as they are not separated, or their transaction gives one another (as a condition) the right of annulling, and if their transaction, has the right of annulling it the transaction becomes binding. Ibn Abi Umar made this addition that whenever he (Ibn Umar) entered into a transaction with a person with the intention of not breaking it, he walked a while and then returned to him.
The Book of Transactions - Sahih Muslim 1531 d
This narration from Ibn Umar (may Allah be pleased with him) establishes the fundamental principle of khiyar al-majlis (option of session) in Islamic commercial law. The hadith indicates that both parties in a transaction retain the right to rescind the agreement so long as they remain together at the place of transaction and have not physically separated.
Scholarly Commentary on Khiyar al-Majlis
The option of session remains valid until the parties depart from one another, whether by physical movement or conclusion of their meeting. This provision serves as a protective measure allowing reconsideration before commitment becomes absolute.
The condition mentioned - "or their transaction gives one another the right of annulling" - refers to khiyar al-shart (stipulated option), where parties may agree upon specific conditions or timeframes for cancellation beyond the initial session.
Practical Application and Wisdom
Ibn Abi Umar's addition demonstrates the Companions' meticulous adherence to this principle. Even with sincere intention to complete a transaction, Ibn Umar would briefly depart and return, thereby conclusively ending the option period and making the contract binding.
This practice embodies the Islamic emphasis on clarity in transactions and protection against hasty decisions, ensuring mutual consent is fully established before obligations become permanent.