أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ الْحَارِثِ، قَالَ حَدَّثَنِي دَاوُدُ بْنُ قَيْسٍ، عَنِ ابْنِ يَسَارٍ، عَنْ أَبِي هُرَيْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ مَنِ اشْتَرَى مُصَرَّاةً فَإِنْ رَضِيَهَا إِذَا حَلَبَهَا فَلْيُمْسِكْهَا وَإِنْ كَرِهَهَا فَلْيَرُدَّهَا وَمَعَهَا صَاعٌ مِنْ تَمْرٍ ‏"‏ ‏.‏

It was narrated from Abu Hurairah that the Messenger of Allah said: "whoever buys a Musarraha, if he is please with it when he milks it, he may keep it, and if he is not please with it, he may return it, along with a Sa of daters"' (Sahih ) Translation Not Available

Book Ref: Sunan An Nisai Book 44 Hadith 4488
Web Ref:  Sunan An Nisai Vol 5 Book 44 Hadith 4493