The Prophet ﷺ used to give us dates from the mixed dates as our ration, and we would exchange them for dates of better quality, paying extra in price. The Messenger of Allah ﷺ said, "A measure of dates for two measures is not permissible, nor a dirham for two dirhams. A dirham is exchanged for a dirham, and a dinar for a dinar, with no difference between them except in weight."
حدثنا أبو كريب حدثنا عبدة بن سليمان عن محمد بن عمرو عن أبي سلمة
كان النبي ﷺ يرزقنا تمرا من تمر الجمع فنستبدل به تمرا هو أطيب منه ونزيد في السعر فقال رسول الله ﷺ لا يصلح صاع تمر بصاعين ولا درهم بدرهمين والدرهم بالدرهم والدينار بالدينار لا فضل بينهما إلا وزنا
Bukhari, Sales, Chapter on Selling Mixed Dates, hadith no. 2080, and Muslim, Sharecropping, Chapter on Selling Food in Equal Measure, hadith no. 1595, from the hadith of Yahya (Ibn Abu Kathir) from Abu Salama, in the same manner.