Rashbam (commenting on the word "le'Os") #1: It means that, when someone wants to curse his enemy, he will wish him to be like you.

Rashbam #2: It means that the punishments are a sign that you did not serve Hakadosh-Baruch-Hu.

Oznayim la'Torah: It implies that, just as, when Yisrael, who are compared to the stars, do the will of Hashem and rise to the heavens, Hashem rewards them in a supernatural way, so too, when they do not do the will of Hashem, and plunge down to the lowest depths, Hashem punishes them in the most unnatural ways. ¹