Numbers 5:15

קמח implies that it shall not be of fine sifted flour. It must be שערים BARLEY, and not wheat; because she committed a bestial act, therefore shall her offering consist of that which is food for beasts (Sifrei Bamidbar 8; Sotah 14a). לא יצק עליו שמן HE SHALL POUR NO OIL UPON IT, so that her offering shall not be embellished (cf. Rashi on Leviticus 5:11) — and also because oil is called light (it is named יצהר from the root צהר, to give light; see Tanchuma) whilst she acted in darkness (Midrash Tanchuma, Nasso 3; cf. Sotah 15a). ולא יתן עליו לבנה NOR SHALL HE PUT FRANKINCENSE THEREON — Because the matriarchs are symbolically termed frankincense, as it is said, (Songs 4:6) “I will get me … to the hill of frankincense” (which is taken as an allusion to the matriarchs), whilst she deviated from their paths (Midrash Tanchuma, Nasso 3). כי מנחת קנאת הוא FOR IT IS A MEAL OFFERING OF JEALOUSY — i.e., this קמח is a meal offering of jealousy; for the word קמח is masculine and is therefore referred to by the masc. form. מנחת קנאת A MEAL OFFERING OF JEALOUSY — The plural קנאות is used because it arouses against her two outbreaks of jealousy — the jealousy of the Omnipresent and the jealousy of her husband (Tosefta Sotah 2; Sifrei Bamidbar 8; cf. Rashi’s second comment on איש איש v. 12).

וְהֵבִ֨יא הָאִ֣ישׁ אֶת־אִשְׁתּוֹ֮ אֶל־הַכֹּהֵן֒ וְהֵבִ֤יא אֶת־קׇרְבָּנָהּ֙ עָלֶ֔יהָ עֲשִׂירִ֥ת הָאֵיפָ֖ה קֶ֣מַח שְׂעֹרִ֑ים לֹֽא־יִצֹ֨ק עָלָ֜יו שֶׁ֗מֶן וְלֹֽא־יִתֵּ֤ן עָלָיו֙ לְבֹנָ֔ה כִּֽי־מִנְחַ֤ת קְנָאֹת֙ ה֔וּא מִנְחַ֥ת זִכָּר֖וֹן מַזְכֶּ֥רֶת עָוֺֽן׃

then shall the man bring his wife to the priest, and he shall bring her offering for her, the tenth part of an efa of barley meal; he shall pour no oil upon it, nor put frankincense on it; for it is an offering of jealousy, an offering of memorial, bringing iniquity to remembrance.