Parashas Naso
וְעָבַ֨ר עָלָ֧יו רֽוּחַ־קִנְאָ֛ה וְקִנֵּ֥א אֶת־אִשְׁתּ֖וֹ וְהִ֣וא נִטְמָ֑אָה אוֹ־עָבַ֨ר עָלָ֤יו רֽוּחַ־קִנְאָה֙ וְקִנֵּ֣א אֶת־אִשְׁתּ֔וֹ וְהִ֖יא לֹ֥א נִטְמָֽאָה׃
but a fit of jealousy has come over him and he is wrought up about the wife who has defiled herself; or if a fit of jealousy has come over him and he is wrought up about his wife although she has not defiled herself:
Torah Temimah points to R’ Meir — TT / Sotah (verified).
ועבר עליו רוח קנאה — תניא, היה ר׳ מאיר אומר: אדם עובר עבירה בסתר והקב״ה מכריז עליו בגלוי.
English: “And a spirit of jealousy passed over him” — it was taught: R’ Meir used to say: A person commits a transgression in secret, and the Holy One proclaims it about him in public.
Custom
Chazal teach that secret sin is brought into the open; the jealousy-spirit initiates that exposure.