What is the meaning of "Terem Tir'un"?
Rashi, Rashbam and Seforno: "You do not yet fear (Hashem)".
Ramban #1 (citing Ibn Ezra): It means before I spread out my hands you fear Hashem, but the moment the plague ceases, you will retract.
Ramban #2: With reference to past occasions,
he pointed out he saw that, before (the cessation of the Makah) the Egyptians fear Hashem, but afterwards not.
Targum Yonasan: Moshe knew that before he sent Yisrael away, he would finally fear Hashem.
As if the Torah had written "Terem Zeh Tir'un" (Ramban).
See also Ba'al ha'Turim.
As happened by the frogs and the wild animals (Ramban).
And that is clearly how it would continue (Ramban.