Sunan Ibn Majah, Volume 3, Book 12, Hadith 2238 (DarusSalam) ⓘ

It was narrated from Ibn 'Umar that the Prophet said: "O Allah, bless my nation in their early mornings.". It was narrated from Abu Hurairah that the Prophet said: "Whoever buys a Musarrah, he has the choice (of annulling the deal) for three days. If he returns it, then he must also give a Sa' of dates, not Samra'." Meaning wheat.

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَلِيُّ بْنُ مُحَمَّدٍ، قَالاَ حَدَّثَنَا أَبُو أُسَامَةَ، عَنْ هِشَامِ بْنِ حَسَّانَ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ ـ صلى الله عليه وسلم ـ قَالَ ‏ "‏ مَنِ ابْتَاعَ مُصَرَّاةً فَهُوَ بِالْخِيَارِ ثَلاَثَةَ أَيَّامٍ فَإِنْ رَدَّهَا رَدَّ مَعَهَا صَاعًا مِنْ تَمْرٍ لاَ سَمْرَاءَ ‏" ‏ ‏.‏ يَعْنِي الْحِنْطَةَ ‏.‏