Nasai

(1) The buying and selling between fresh and dried dates is prohibited because fresh dates, after drying, will decrease in quantity, and in items of the same kind, disparity (in quantity) is not permissible. However, in the sale of ‘ariyah (a specific concession), it is permissible to transact fresh dates for dried dates, because otherwise, it would create difficulties for both parties, i.e., the giver and the receiver of the gift, as the one giving the gift would be compelled not to give it.

(2) This hadith indicates that when fresh fruit of the same kind decreases in weight after drying, then the mutual sale of dried and fresh fruit of that kind is forbidden, even if at the time of transaction both (types of fruit) are equal in weight and measure. The reason is that equality, i.e., mutual equivalence, is only considered valid and correct when those items remain equal even after reaching their final state, and this is not the case here, because when dates dry, their weight inevitably becomes less than in their fresh state, and it is also impossible to determine exactly how much the weight decreases. However, Imam Abu Hanifah rahimahullah considers the mutual sale of dried and fresh dates permissible if the weight and measure are equal, whereas his two companions (the students of the Imam, Imam Muhammad ibn al-Hasan and Imam Abu Yusuf) oppose their respected teacher in this issue, and based on the authentic hadiths regarding the prohibition in this matter, they accepted the hadith of the Messenger and rejected the statement of their teacher. For further details, see: (Dhakheerat al-‘Uqba Sharh Sunan al-Nasa’i by al-‘Atyubi: 34/275)

(3) This type of sale is called muzabanah. Generally, it is prohibited, but in the case of ‘ariyah (trees given as a gift), a concession has been granted for the ease of the poor, as has already been explained in detail in benefit number .
(For further details, see hadith number: 3910)