عَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ مَرَّ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ بِطَعَامٍ وَقَدْ حَسَّنَهُ صَاحِبُهُ فَأَدْخَلَ يَدَهُ فِيهِ فَإِذَا طَعَامٌ رَدِيءٌ فَقَالَ بِعْ هَذَا عَلَى حِدَةٍ وَهَذَا عَلَى حِدَةٍ فَمَنْ غَشَّنَا فَلَيْسَ مِنَّا
It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) passed by a heap of grain. Its owner had arranged it in a very beautiful manner. When the Prophet (peace and blessings be upon him) put his blessed hand inside it, he found that it was inferior grain. The Prophet (peace and blessings be upon him) said to him: "Sell this separately and that separately. Whoever deceives us is not from us."