62:4 When selling an item, we are not permitted to make it look more attractive in order to trick the buyer into overestimating its value. For example, one may not feed an animal things that would make it swell or do other things to make it appear fatter than it is. One may likewise not paint old utensils in order to make them look new and other such deceptions.
62:5 It is forbidden to slip bad pieces of fruit into a volume of good pieces with the intention to sell the whole lot as good fruit. One may likewise not mix some bad drink with good with the intention to deceive. However, if it is obvious from the taste, then it is permitted because the buyer will notice.