Negative commandment · Lo Ta’aseh #31 of 613
Not to practice black magic
שלא לקסום
The verse · Devarim 18:10
לֹא־יִמָּצֵא בְךָ מַעֲבִיר בְּנוֹ־וּבִתּוֹ בָּאֵשׁ קֹסֵם קְסָמִים מְעוֹנֵן וּמְנַחֵשׁ וּמְכַשֵּׁף
“There must not be found among you anyone that makes his son or his daughter to pass through the fire, or that uses divination, a soothsayer, or an enchanter, or a witch,”
The Rambam’s words
Not to practice black magic, as [Deuteronomy 18:10] states: "There shall not be found among you... a magician."
שלא לקסום, שנאמר "לא יימצא בך . . . קוסם קסמים" (דברים יח,י).
Who & when
“And this prohibition is practiced in every place and at all times by males and females.”
Where in the Mishneh Torah
Hilchot Foreign Worship and Customs of the Nations הלכות עבודה זרה וחוקות הגויים