Leviticus 20:27

'‎כי יהיה בהם אוב וגו‎ [A MAN ALSO, OR A WOMAN] THAT HATH THE SPIRIT אוב, [OR THAT IS A WIZARD SHALL SURELY BE PUT TO DEATH] — Here the penalty of death by stoning is mentioned for them, and above (Leviticus 20:6) it mentions excision! But the explanation is: If there were witnesses to the offence and the necessary warning had been given them, death by stoning is the punishment. If he acted wittingly but had not been warned, he is punishable with excision and if he breaks the law regarding them (the אוב or ידעוני) inadvertently, he has to bring a sin offering. And the same rules apply in the case of all persons who are subject to the death penalty, where excision is mentioned (i. e. in all such cases “stoning" or a sin offering is the punishment according to the circumstances).

וְאִ֣ישׁ אֽוֹ־אִשָּׁ֗ה כִּי־יִהְיֶ֨ה בָהֶ֥ם א֛וֹב א֥וֹ יִדְּעֹנִ֖י מ֣וֹת יוּמָ֑תוּ בָּאֶ֛בֶן יִרְגְּמ֥וּ אֹתָ֖ם דְּמֵיהֶ֥ם בָּֽם׃ {פ}

A man also or woman that is a medium or a wizard, shall surely be put to death: they shall stone them with stones: their blood shall be upon them.