Sunan an-Nasa'i, Volume 5, Book 44, Hadith 4493 (DarusSalam) ⓘ
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 )
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 " .
also referenced under: Hadith 4488 (Reference) & Book 44, Hadith 40 (In-Book)