The Alter of Slabodka writes that the plagues with which the Egyptians were punished, additionally served to demonstrate hashgacha pratis (individual providence). Although the Egyptians were paralyzed by the darkness, simultaneously, the Jewish People enjoyed the light illuminating their dwelling places. Moreover, Chazal tell us that during the first plague of blood a Jew and Egyptian could drink from the same glass of water, and the Jew would taste water while the Egyptian would only end up swallowing blood. This was the ultimate proof that each person lives in his own personal world. At the very same time that the Egyptian’s world was filled with blood and darkness, the world of each Jew was filled with light and an ample supply of water.

            Rav Wolbe (Shiurei Chumash Parshas Bo ) notes that this concept is expressed by Chazal