Parashas Naso
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׃
That man shall bring his wife to the priest. And he shall bring as an offering for her one-tenth of an ephah of barley flour. No oil shall be poured upon it and no frankincense shall be laid on it, for it is a grain offering of jealousy, a grain offering of remembrance that recalls wrongdoing.
Torah Temimah points to TT / Sotah (verified).
והביא האיש את אשתו — מלמד שהאיש מביא את אשתו אל הכהן, ואפילו הכי אמרו חכמים מוסרים לו שני תלמידי חכמים.
English: “And the man shall bring his wife” — this teaches that the husband brings his wife to the kohen; even so the Sages said that two Torah scholars are assigned to him lest he cohabit with her on the way.
Custom
Chazal require the husband’s initiative and add the escort of two scholars to protect the integrity of the ordeal.