Are all the dates of Khaibar like this? He said: Messenger of Allah, 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 Messenger of Allah 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.
أَنَّ رَسُولَ اللَّهِ ﷺ بَعَثَ أَخَا بَنِي عَدِيٍّ الأَنْصَارِيَّ فَاسْتَعْمَلَهُ عَلَى خَيْبَرَ فَقَدِمَ بِتَمْرٍ جَنِيبٍ فَقَالَ لَهُ رَسُولُ اللَّهِ ﷺ أَكُلُّ تَمْرِ خَيْبَرَ هَكَذَا قَالَ لاَ وَاللَّهِ يَا رَسُولَ اللَّهِ إِنَّا لَنَشْتَرِي الصَّاعَ بِالصَّاعَيْنِ مِنَ الْجَمْعِ فَقَالَ رَسُولُ اللَّهِ ﷺ لاَ تَفْعَلُوا وَلَكِنْ مِثْلاً بِمِثْلٍ أَوْ بِيعُوا هَذَا وَاشْتَرُوا بِثَمَنِهِ مِنْ هَذَا وَكَذَلِكَ الْمِيزَانُ