Not to practice divination by observing omens

He prohibited us from divination - meaning to say, that one moves the faculty of imagination with a type of stimulus, like all of those with abilities to say what will happen before it does. Indeed, it comes true for them - since their imaginative faculty is strong, their words mostly come true. And hence they will rely upon their [predictions], and they will have an advantage with this, like [any] advantage of the personal skill of some people over others in any abilities of the spirit. And it is impossible for any of the people with these imaginative faculties without [first] doing some deed or action with which to stimulate his faculty and to bring his [imaginative] activity into effect. And among them is one who strikes the ground with a stick that is in his hand - repetitive strikes - and yells unusually, ignores his thoughts and stares at the earth a long time until he is visited by effects of a seizure, and tells over what will happen in the future. And I have already seen this a few times in the far West. [Also] among them is one who spreads out sand and shapes forms in it; and this is very famous in the West. And among them [as well] is one who throws smalls stones onto a strip of leather and studies them and afterwards speaks out words. And this is well-known and famous in every place that I have gone. And [also] among them is one who throws a long leather belt to the floor, observes it and reveals hidden things. And the intention in [all of] this is to stimulate the imaginative faculty with it; not that the action does something on its own or indicates the [specific] matter. And the masses err in this. For since some of the reports are correct, they think that these actions are what indicate what will be - [such] that this error comes to them to the point that they think that some of these actions are the cause of what will be, like some of the astrologers think. For astrology involves the same relationship - meaning that [the movement of the stars] are a type of stimulus of the imaginative faculty and arouse it. And hence no two men will be the same in their revealing that which is hidden, even if they are the same in their knowledge of the discipline. And anyone who does any of these acts and other ones that follow in this way is called a diviner; and He said, "Let no one be found among you who is a diviner" (Deuteronomy 18:10). And the language of the Sifrei (Sifrei Devarim 171:6) is, "Which is a diviner? It is one who holds his stick and says whether I should go or whether I should not go." And this was a famous type of stimulus at that time - the prophet said (Hosea 4:12) "My people consults its stick; its rod tells it (what to do)." And one who transgresses this negative commandment and does one of these [things] - meaning one who divines and speaks to people from an action that moves him - is liable for lashes; [but] not the one that asks the diviner. However asking the diviner is very vile. And the regulations of this commandment have already been explained in Tractate Sanhedrin. (See Parashat Shoftim; Mishneh Torah, Foreign Worship and Customs of the Nations 11.)