Four Statutes the Evil Inclination Loves to Argue Against

Rabbi Joshua of Sikhnin in the name of Rabbi Levi: There are four matters that the evil inclination argues against, and concerning all of them "statute" is written. And these are they: a brother's wife, mixed kinds, the goat that is sent away, and the heifer. A brother's wife, from where? "The nakedness of your brother's wife you shall not uncover" (Leviticus 18:16), yet it is written, "Her brother-in-law shall come upon her" and so on (Deuteronomy 25:5): during his lifetime she is forbidden; if he dies without children she is permitted to him; and "statute" is written concerning it, "You shall keep My statutes and My ordinances which a person shall do" and so on (Leviticus 18:5). Mixed kinds, from where? "You shall not wear shaatnez" and so on (Deuteronomy 22:11), yet a linen garment with woolen fringes is permitted; and "statute" is written concerning it, "You shall keep My statutes" and so on (Leviticus 19:19). The goat that is sent away, from where? "And the one who sends away the goat to Azazel" (Leviticus 16:26): it itself atones for others [yet defiles the one who handles it]; and "statute" is written concerning it, "And this shall be for you an everlasting statute" (Leviticus 16:29). The heifer, from where? There we learned: all who are occupied with the heifer from beginning to end render their garments impure, yet it itself purifies the impure; and "statute" is written concerning it, "This is the statute of the Torah" (Numbers 19:2).