Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 310
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 310, with English translation by Maimonides (Rambam).
שלא להחיות מכשף, שנאמר "מכשפה, לא תחייה" (שמות כב,יז).
Not to allow a sorcerer to live, as [Exodus 22:17] states: "Do not allow a witch to live."