It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that once the Prophet (peace and blessings be upon him) was walking along the road when he saw a pile of grain which its owner had arranged very nicely. The Prophet (peace and blessings be upon him) put his hand inside it and found that the grain inside was of poor quality. The Prophet (peace and blessings be upon him) said: "Sell this separately. Whoever deceives us is not from among us."