صحيح مسلم

Abu Huraira and Abu Sa'id al-Khudri (Allah be pleased with them) reported that Allah's Messenger (ﷺ) deputed a person from Banu 'Adi al-Ansari to collect revenue from Khaibar. He came with a fine quality of dates, whereupon Allah's Messenger (ﷺ) said to him: Are all the dates of Khaibar like this? He said: Allah's Messenger, it is not so. We buy one sa' of (fine quality of dates) for two sa's out of total output (including even the inferior quality of dates), whereupon Allah's Messenger (ﷺ) said: Don't do that, but like for like, or sell this (the inferior quality and receive the price) and then buy with the price of that, and that would make up the measure.