The Laws of Commerce and Trade
4. A person who has merchandise to sell cannot make it appear more
attractive [then it actually is], in order to deceive the purchaser. For
example, it is prohibited to feed an animal bran-water in order for its
body to swell and its hair to stand up straight, so that it will appear
fat. Similarly, one may not repaint old utensils so that they will appear new.
5. Similarly, it is forbidden to mix some inferior produce with a large
quantity of superior produce, in order for the entire amount to appear
superior. Also, it is forbidden to mix inferior beverages with a superior
blend. If the taste of the inferior blend is noticeable, it is permitted,
since the purchaser will detect it.
6. A storekeeper is permitted to distribute roasted seeds and nuts to
children to attract them to purchase [other things] from him. Similarly,
one may sell certain items below the market price, so that customers will
purchase from him. Other merchants cannot prevent him from doing so.