מְכַשֵּׁפָ֖ה לֹ֥א תְחַיֶּֽה׃ (ס)
Wróżki przy życiu nie zostawisz.
Rashi
מכשפה לא תחיה THOU SHALT NOT SUFFER A WITCH TO LIVE — This does not mean that you may kill her but she shall be put to death by the court. Both men and women who practise witchcraft are included in this law but in using the feminine term מכשפה Scripture speaks of what is usually the case; for it is women who mostly practise witchcraft (Sanhedrin 67a).
Chizkuni
מכשפה לא תחיה, “You must not allow asorceress to remain alive.” The reason why this apparently unrelated subject follows on the heels of how to deal with seducers is that people who seek ways and means to gratify their illegal sexual urges, turn to sorceresses to help them do so.
Ramban
THOU SHALT NOT SUFFER A SORCERESS TO LIVE. In connection with all those who are guilty of death, He has said above: moth yumoth (he shall be surely put to death),273Above 21:15-17. meaning he is liable to death, and it is a positive commandment upon us to slay him, based upon the verse which says, And thou shalt put away the evil from the midst of thee,274Deuteronomy 17:7. Ramban is here intimating that this verse is the basis for the one commandment of the execution of all four modes of death penalties. Rabbi Moshe ben Maimon (Rambam) counted them as four separate commandments. See my translation, “The Commandments,” Vol. I, p. 240. or it may be that this obligation on us is derived from the very expression yumoth (he shall be put to death) which He used in these cases.275This opinion corresponds closely to that of the author of ‘Hilchoth Gedoloth’ which Rambam in his Sefer Hamitzvoth criticised, and Ramban in his notes to that work defended. See “The Commandments,” Vol. II, p. 420. But here, however, He did not say, “a sorceress shall be put to death,” but in this case He warned us in a stricter manner by means of a negative commandment, that we should not suffer her to live.276See ibid., pp. 285-286. The reason for this is that the sorceress is defiled of name and full of tumult,277Ezekiel 22:5. and fools are mislead by her, therefore He was more stringent and admonished us with a prohibition. We find a similar severity in relation to all those who cause snares for many people, such as that which He said in the case of the misleader after idols, neither shalt thou spare, nor shalt thou conceal him,278Deuteronomy 13:9. and in the case of a murderer He said, And ye shall take no ransom for the life of a murderer, that is guilty of death.279Numbers 35:31.