The Prophet ﷺ said: If anyone buys a sheep whose udders have been tied up, he has option for three days (for decision). If he returns it, he should return with it wheat equal to its milk or double of it.  

قَالَ رَسُولُ اللَّهِ ﷺ مَنِ ابْتَاعَ مُحَفَّلَةً فَهُوَ بِالْخِيَارِ ثَلاَثَةَ أَيَّامٍ فَإِنْ رَدَّهَا رَدَّ مَعَهَا مِثْلَ أَوْ مِثْلَىْ لَبَنِهَا قَمْحًا  

"The Messenger of Allah ﷺ said: 'Whoever buys a Muhaffalah, (1) he has the choice (of annulling the deal) for three days. If he returns it, then he must also give wheat equal to twice, the amount of its milk, or equal to the amount of its milk."'  

قَالَ رَسُولُ اللَّهِ ﷺ يَا أَيُّهَا النَّاسُ مَنْ بَاعَ مُحَفَّلَةً فَهُوَ بِالْخِيَارِ ثَلاَثَةَ أَيَّامٍ فَإِنْ رَدَّهَا رَدَّ مَعَهَا مِثْلَىْ لَبَنِهَا أَوْ قَالَ مِثْلَ لَبَنِهَا قَمْحًا  

"يَا أَيُّهَا النَّاسُ: لا يَتَلقَّيَنَّ أَحدٌ مِنْكُمْ سُوقًا، وَلا يَبِيعَنَّ مُهَاجِرٌ لأَعْرَابِىٍّ، وَمَنِ ابْتَاعَ مُحَفَّلةً فَهُوَ بِالْخِيَارِ ثَلاثَةَ أَيَّامٍ، فَإِنْ رَدَّهًا رَدَّ مَعَهَا مِثْلَ -أَوْ قَالَ- مِثْلَى -لَبَنِهَا قَمْحًا".