Rashi on Numbers 5:14/רש"י על במדבר ה׳:י״ד

1ועבר עליו AND [THE SPIRIT OF JEALOUSY] COME UPON HIM — i.e., had come upon him before her seclusion with the man.

2רוח קנאה וקנא [AND] THE SPIRIT OF JEALOUSY [COME UPON HIM] וקנא — Our Rabbis said that it is an expression denoting warning — that he warns her: do not be aside privily with that man (Sotah 3a.)

3והוא נטמאה או עבר עליו וגו׳ AND SHE BE DEFILED, OR IF [THE SPIRIT OF JEALOUSY] COME UPON HIM [AND SHE WAS NOT DEFILED] — that is to say, he warned her but she disregarded his warning, and it is uncertain whether she has been defiled or not (Sifrei Bamidbar 8).