To not invoke a charm: That we have been prevented from making invocations over anything. And this matter is that a man say things, and say to people that those things [he said] benefit or damage anything. And about this is it stated (Deuteronomy 18:10-11), “There shall not be found in you, etc. And one who invokes charms.” And the language of Sifrei Devarim 172 [is] “It is one if he charms a snake or if he charms a scorpion” — meaning to say, that he says to them things, so that they will not bite him, according to his opinion. (See Sefer HaMitzvot, Negative Commandments 35.) And so [too, included] is one who says things over his wound, in order that the pain will leave him. And there are some that explained “one who invokes charms,” [to mean] that he gathers snakes or scorpions or other animals to one place with his machinations and his invocations. And it is all included in the prohibition.

And maybe, my son, you will challenge me with that which we have the textual version in Shevuot 15b in the chapter [entitled] Yediot HaTumah, “The song of disturbances (pegaim) with harps and lyres. [...] And he says, ‘He that dwells in the secret place of the Most High,’ until ‘Because You, O Lord, are my refuge’ (Psalms 91:1-9). And he says, ‘Lord, how many have my enemies become,’ until ‘Salvation belongs to the Lord’ (Psalms 3:2-9).” And the understanding of “disturbances” is meaning to say that the saying of these psalms is beneficial in protection from damages (evil spirits). And they [further] said in Berakhot (see Rif 3a on Berakhot), “Rabbi Yehoshua ben Levi would order these verses and fall asleep.” However the matter is not, God forbid, similar to the matter of invoking a charm that we mentioned. And they, may their memory be blessed, have already mentioned (Shevuot 15b), “One is prohibited from healing himself with words of Torah.” Rather they mentioned to say these psalms that have things that arouse the soul of the one that knows them, to take refuge in God, may He be blessed, to put all of his trust in Him, to fix His awe in his heart and to rely upon His kindness and His goodness. And from the arousal to this, he will be protected, without a doubt, from all damage. And this is what they answered in the Gemara about this matter, as it challenged there, “And how could Rabbi Yehoshua do that? But doesn’t Rabbi Yehoshua say, ‘One is prohibited from healing himself with words of Torah?’” and they said, “To protect is different” — meaning to say, the Torah did not forbid that a person say words of Torah to arouse his soul to the good, so that this merit protect him to guard him.

What I have written on the commandment that preceded it is from the roots of this commandment.

The laws of the commandment are in the seventh chapter of Shabbat.

And this prohibition is practiced in every place and at all times by males and females. And one who transgresses it and makes an invocation volitionally is liable for lashes.