Muwatta Malik, Book 31, Hadith 1313 (In-Book) ⓘ

Yahya related to me from Malik from Zayd ibn Aslam that Ata ibn Yasar said, "The Messenger of Allah, may Allah bless him and grant him peace, said, 'Dried dates for dried dates is like for like.' It was said to him, 'Your agent in Khaybar takes one sa for two.' The Messenger of Allah, may Allah bless him and grant him peace, said, 'all him to me.' So he was called for. The Messenger of Allah, may Allah bless him and grant him peace, asked, 'Do you take one sa for two?' He replied, 'Messengerof Allah! Why should they sell me good dates for assorted low quality dates, sa for sa!' The Messenger of Allah, may Allah bless him and grant him peace, said, 'Sell the assorted ones for dirhams, and then buy the good ones with those dirhams.' "

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، أَنَّهُ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ التَّمْرُ بِالتَّمْرِ مِثْلاً بِمِثْلٍ ‏"‏ ‏.‏ فَقِيلَ لَهُ إِنَّ عَامِلَكَ عَلَى خَيْبَرَ يَأْخُذُ الصَّاعَ بِالصَّاعَيْنِ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ ادْعُوهُ لِي ‏"‏ ‏.‏ فَدُعِيَ لَهُ فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ أَتَأْخُذُ الصَّاعَ بِالصَّاعَيْنِ ‏"‏ ‏.‏ فَقَالَ يَا رَسُولَ اللَّهِ لاَ يَبِيعُونَنِي الْجَنِيبَ بِالْجَمْعِ صَاعًا بِصَاعٍ ‏.‏ فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ بِعِ الْجَمْعَ بِالدَّرَاهِمِ ثُمَّ ابْتَعْ بِالدَّرَاهِمِ جَنِيبًا ‏"‏ ‏.‏