Sahih Bukhari Volume 5, Book 64, Hadith 4247

حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ عَبْدِ الْمَجِيدِ بْنِ سُهَيْلٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، وَأَبِي، هُرَيْرَةَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم اسْتَعْمَلَ رَجُلاً عَلَى خَيْبَرَ، فَجَاءَهُ بِتَمْرٍ جَنِيبٍ، فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ كُلُّ تَمْرِ خَيْبَرَ هَكَذَا ‏"‏‏.‏ فَقَالَ لاَ وَاللَّهِ يَا رَسُولَ اللَّهِ، إِنَّا لَنَأْخُذُ الصَّاعَ مِنْ هَذَا بِالصَّاعَيْنِ ‏{‏وَالصَّاعَيْنِ‏}‏ بِالثَّلاَثَةِ‏.‏ فَقَالَ ‏"‏ لاَ تَفْعَلْ، بِعِ الْجَمْعَ بِالدَّرَاهِمِ، ثُمَّ ابْتَعْ بِالدَّرَاهِمِ جَنِيبًا ‏"

Narrated By Abu Said Al-Khudri and Abu Huraira : Allah's Apostle appointed a man as the ruler of Khaibar who later brought some Janib (i.e. dates of good quality) to the Prophet. On that, Allah's Apostle said (to him). "Are all the dates of Khaibar like this?" He said, "No, by Allah, O Allah's Apostle! But we take one Sa of these (dates of good quality) for two or three Sa's of other dates (of inferior quality)." On that, Allah's Apostle said, "Do not do so, but first sell the inferior quality dates for money and then with that money, buy Janib."