"The Prophet said: ' A heap of grain should not be sold for a heap of grain, or for a heap of grain of known measure. "  

قَالَ النَّبِيُّ ﷺ لاَ تُبَاعُ الصُّبْرَةُ مِنَ الطَّعَامِ بِالصُّبْرَةِ مِنَ الطَّعَامِ وَلاَ الصُّبْرَةُ مِنَ الطَّعَامِ بِالْكَيْلِ الْمُسَمَّى مِنَ الطَّعَامِ