The 32nd prohibition is that we are forbidden from acting according to the guidelines of astrology, i.e. "this day is auspicious for doing this action, and we will therefore do it," or "this day is not auspicious for doing this action, and we will therefore not do it."

The source of this commandment is G‑d's statement (exalted be He),1 "Among you there shall not be found anyone...who divines auspicious times [m'onen]." This prohibition has been repeated in G‑d's statement,2 "Do not act on the basis of auspicious times [lo t'oneinu]."

In the words of the Sifra, "Lo t'oneinu means that you may not assign times." The root of the [Hebrew] word is onah [time], and the meaning is that a person should not establish times and say one time is good and another time is bad.

One who transgresses this prohibition is also3 punished by lashes. This refers to the one who advises4 regarding the times, not the one who asked. Asking [the astrologer], however, is also prohibited, in addition to [the entire practice] being false. One who thinks that a particular time is lucky, or that it will bring him success in a particular action, and acts based on that belief is punished by lashes, since he performed an action.

Included in this prohibition is making optical illusions. In the words of our Sages,5 "A m'onen refers to one who deceives through optical illusions.6 This covers a broad category of tricks and sleight of hand, causing people to believe things which are untrue. We frequently see people who perform in this way — he takes a rope, puts it in his pocket for everyone to see, and then pulls out a snake; or he throws a ring into the air and then removes it from the mouth of a person standing before him, and similar optical illusions well known to the masses. All these are forbidden, and one who performs any of them is called "ocheiz es ha'eina'im" [one who does optical illusions"], which is a type of witchcraft, and he is therefore punished by lashes.

He is also deceiving people,7 and causes tremendous damage by leading fools, women, and children to view things which are impossible as being possible. Their mind then becomes accustomed to accept the impossible, and to think that it is also possible.

This should be well understood.