The Messenger of Allah ﷺ forbade the sale of a heap of dates whose measure is unknown in exchange for a specified measure of dates.
نهي رسول الله ﷺ عن بيع الصبرة من التمر، لا يعلم مكيلها بالكيل المسمى من التمر.
Muslim narrated it in the Book of Sales (1530), from Abu Tahir Ahmad bin Amr bin Sarh, who said, Ibn Wahb told us, Ibn Jurayj told me, that Abu Zubayr informed him that he heard Jabir bin Abdullah say what he mentioned.Nasai narrated it (4548) through another route, from Hajjaj, who said, Ibn Jurayj said, Abu Zubayr informed me that he heard Jabir bin Abdullah say, the Prophet ﷺ said, "A heap of food may not be sold for a heap of food, nor may a heap of food be sold for a specified measure of food."The word "subrah" means a heap. It is said, "He bought the thing as a subrah," meaning without weighing or measuring it.