He who buys a goat with its udder tied up has the option to retain the goat if he so desires or return it within three days, and in case he returns it he should do so along with a sa' of dates. (Using translation from Muslim 1524b)   

أَنَّ رَسُولَ اللهِ ﷺ قَالَ مَنِ ابْتَاعَ شَاةً مُصَرَّاةً فَهُوَ بِالْخِيَارِ ثَلَاثَةَ أَيَّامٍ إِنْ شَاءَ أَمْسَكَهَا وَإِنْ شَاءَ رَدَّهَا وَرَدَّ مَعَهَا صَاعًا مِنْ تَمْرٍ  

[Machine] The Messenger of Allah ﷺ said, "Whoever buys a domestic camel has the choice for three days: if he returns it, he returns it and gives a measure of food, not red (meat)."  

قَالَ رَسُولُ اللهِ ﷺ مَنِ اشْتَرَى مُصَرَّاةً فَهُوَ بِالْخِيَارِ ثَلَاثَةَ أَيَّامٍ فَإِنْ رَدَّهَا رَدَّهَا وَصَاعًا مِنْ طَعَامٍ لَا سَمْرَاءَ