He was anxious to safeguard Muslims against indulgence in any form of unfairness in their transactions. Passing through the market-place on one occasion, he observed a heap of corn which was being put to auction. He thrust his arm into the heap and found that though the outer layer of the corn was dry the corn inside was wet. He inquired from the owner the cause of this. The man explained that a sudden shower of rain had made part of the corn wet. The Prophet(sa) said that in that case he should have allowed the wet layer of corn to remain on the outside so that prospective purchasers could have appraised its real condition. He observed: "He who deals unfairly with others can never become a useful member of society" (Muslim). He insisted upon trade and commerce being entirely free from every suspicion of sharp practice. He exhorted purchasers always to inspect the goods and articles they proposed to purchase, and forbade any person to open negotiations for a transaction while negotiations about it were in progress with any other person. He also forbade the hoarding of commodities against a rise in the market and insisted that the market should be regularly supplied.