And this is also the root of the matter that in those days when the plague of blood prevailed, the Egyptians had to purchase drinking water from the Israelites with full payment – thus rectifying their compulsion against the goodwill of Yosef, who in exchange for providing for them and saving their lives, they repaid him with evil instead of good. Now, they would be forced to pay in full for the necessary drinking water to sustain their lives.

We also find with the plague of frogs, that recognizing the good for their lives is seen in the treasures of the wonders of Torah, and thus they were rewarded that Chananiah, Mishael, and Azariah learned from them to risk their lives.

And this is the idea I wanted to express here, that it is fitting that this lesson of the obligation of recognizing the good is learned from the fact that it was Aharon who brought these two plagues and not Moshe – it is established here, in these two plagues, since the essence of these plagues is based and founded on the matter of recognizing and enforcing gratitude.