Sforno on Numbers 5:29/ספורנו על במדבר ה׳:כ״ט

1זאת תורת הקנאות; jealousy which is legally approved on the one hand, and jealousy which is legally not approved. This becomes clear from the words אשר תשטה אשה תחת אישה ונטמאה, this is the example of the legally justified jealousy. The Torah goes on to write או איש אשר תעבור עליו רוח קנאה, as an example of legally unjustified jealousy.