Chapter on Conditions and Options in Sales
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 2|Chapter 8
وَ قَالَ عَلَيْهِ اَلسَّلاَمُ: "أَيُّمَا رَجُلٍ اِشْتَرَى مِنْ رَجُلٍ بَيْعاً فَهُمَا بِالْخِيَارِ حَتَّى يَفْتَرِقَا فَإِذَا اِفْتَرَقَا فَقَدْ وَجَبَ اَلْبَيْعُ".
Imam عليه السلام said: "Whenever a man buys something from another man, they both have the option (to cancel the deal) until they part ways. Once they part, the sale becomes binding."
- Ṣaḥīḥ al-Faqīh