Deuteronomy 17:3-5

and has gone and served other gods and worshiped them, or the sun or the moon or any of the heavenly host, which I have not commanded, and if it is told you and you have heard of it, then you shall inquire thoroughly. Behold, if it is true and the thing certain that this detestable thing has been done in Israel, then you shall bring out that man or that woman who has done this evil deed to your gates, that is, the man or the woman, and you shall stone them to death.