Sefer HaChinuch ספר החינוך

To not soothsay: To not soothsay, as it is stated (Leviticus 19:26), “and you shall not soothsay (teonenu).” And the understanding of the matter is like they said in Sifra, Kedoshim, Chapter 6:2, that it is an expression of a time period (onah). [This] means to say that we do not fix time periods to say time x is good to do action y; and anyone who does it at that time will be successful, but one who does it at time z will not be successful — like the empty clairvoyants say. And the negative commandment about this matter is repeated in the Order of Shoftim, as it is written there (Deuteronomy 18:10), “There shall not be found in you, etc. a soothsayer.” And they, may their memory be blessed, said (Sanhedrin 65b) that included in this negative commandment of the soothsayer is the fooling the eyes that people do. And this matter is a great type of machination that is connected with lightness of hand and its powerful quickness to the point that it appears to people that the trickster is doing fantastic things, meaning to say that they are supernatural. As what those that make efforts in this always do, such that they take a rope and put it into the corner of their clothes in front of people’s eyes, and afterwards they take out a snake; and so [too,] they throw a ring into the air, and afterwards they take it out from the mouth of one of the bystanders in front of them; and many things similar to these. And each one of these evil acts is forbidden, and one who does it is called a fooler of the eyes. And it is included in the prohibition of the soothsayer and we administer lashes for it. And even though [the prohibition of the] soothsayer is stated next to the sorcerer in one verse, it is not precisely a type of magic. As if the prohibition about it was on account of the negative commandment of the sorcerer, we would not administer lashes for it, since the negative commandment of the sorcerer is given over to the warning of a death penalty from the court, as it is stated (Exodus 22:17), “You shall not keep a witch alive.” And it is established for us (Eruvin 17b) that we do not administer lashes for any negative commandment that is given over to the warning of a death penalty from the court.

What we wrote about the negative commandment of the diviner adjacently is from the roots of the commandment. And there is another very great damage that is found with this, since it will [cause that] the masses and the women and the youths will accept that which is completely impossible as possible. And it will be sweet for their minds to accept the impossible and that it be possible without the matter of a miracle from the Creator. And perhaps a bad outcome will result from this for them; to deny a fundamental principle, and their souls will be excised — and understand this. The details of the commandment are there in Sifra and in [various] places in the Gemara and in the Midrash.

And this prohibition is practiced in every place and at all times by males and females. And one who transgresses it and says time periods to people that they should perform their actions in order that they be successful — and also the one who does his actions according to [these] time periods — is liable for lashes. And a man who asks of one who knows [these time periods] does not have a liability for lashes with the question alone, until he designs his action to be with the known time, and does his work during it. And then is he lashed on its account, since he did an act.