Allah's Messenger (ﷺ) forbade al-Muzabanah, which means that a man sells the fruit of his garden, if it consists of palm-trees (fresh dates), for dried dates by measure; or if it consists of grapes (on the vines), for raisins by measure; or if it is unpicked crops, he sells it for a measured amount of picked crops. He forbade all that. [Agreed upon]. Narrated Sa'd bin Abu Waqqas (RA): I heard Allah's Messenger (ﷺ) being asked about buying fresh dates for dry ones. He replied, "Will fresh dates diminish when they become dry?" They answered, "Yes." So he forbade that. [Reported by al-Khamsah and graded Sahih (authentic) by Ibn al-Madini, at-Tirmidhi, Ibn Hibban and al-Hakim].