Sayyiduna Bilal (may Allah be pleased with him) said: I had a mudd of dates belonging to the Prophet (peace and blessings be upon him). I got better quality dates in exchange for one sa’ with two sa’s, and I bought them. I brought them to the Prophet (peace and blessings be upon him), and he said:“Where did you get these dates from?”I said: I bought one sa’ in exchange for two sa’s. The Prophet (peace and blessings be upon him) said:“Return them and give us back our dates.”

Sayyiduna Abu Sa'id Khudri and Sayyiduna Abu Hurairah (may Allah be pleased with them both) narrated that the Messenger of Allah (peace and blessings be upon him) appointed the brother of Banu 'Adi as an official (officer or collector) for Khaybar. He brought back Janib (a type of good quality date) from there. The Messenger of Allah (peace and blessings be upon him) asked him: "Are all the dates of Khaybar like this (excellent)?" He replied: "By Allah, O Messenger of Allah! Not all are like this. We give two sa' of Jam' (a type of inferior date) in exchange for one sa' of this (Janib)." The Messenger of Allah (peace and blessings be upon him) said: "Do not do so. Rather, buy and sell in equal measure (weight and volume), or sell the inferior dates and buy Janib (good dates) with its price. And do the same with items that are measured by weight."