Hashem said to Moshe, “Say to Aharon, ‘Take your staff and stretch forth your hand over the waters of Egypt, their rivers, canals, ponds and over all their bodies of water, and they will become blood'”.
Rashi elucidates the intervention of Aharon: Since the Nile protected Moshe when he was cast into it, therefore it was not smitten by him, neither for the plague of blood nor that of frogs, but was smitten by Aharon.
Not everybody was qualified to implement the plagues on Egypt, Moshe and Aharon, two outstanding men, prophets, were charged with this celestial duty. Only men of caliber were entrusted with performing these miracles. These phenomena had a dual purpose, retribution and education. Retribution for Egypt’s cruel treatment of the Jews. Additionally they educated the entire world that not only is there is a G-d but He supervises the activities and machinations of man.
Classifying involvement in the Makkos as a chance to draw close to Hashem and an avenue of spiritual growth would constitute a gross understatement. This was a charge of the highest order, a golden opportunity. If so how can Moshe be excluded from this Mitzvah of punishing the wicked Mitzrayim, people who wanted to cast him in the water, because the water protected him. What about the Mitzvah? Why pass up on the religious experience?
There is a mitzvah to kill evil people and eradicate evil from our midst (Devorim 21:21). Murder, however makes a man merciless, even justified executions cultivate a callous attitude towards life. The court that is involved in massacring a wayward city, a large scale extermination, are specifically guaranteed a gift from Hashem – Mercy. Since this massive carnage would undoubtedly make them hardhearted and cruel, Hashem promises them he will give them an extra measure of Rachamim.
Hitting the Nile to turn into blood was to provide a tremendous connection with Hashem for the assigned striker. But for Moshe who was protected by the Nile, it would breed feelings of ingratitude. Moshe who was sheltered in its waters and was saved hidden in its rushes, owed a debt of gratitude to the Nile. To now turn these waters into an instrument inflicting harm on his former attackers would be spiritually unhealthy. He would begin to resent objects and people that benefited him. G-d forbid he should develop into an unappreciative person. It was therefore more ideal, that Aharon hit the Nile in his stead.
Reb Nosson Zvi Finkel (1849 – 1927) known as the Alter of Slabodka was an influential leader in Eastern Europe and founder of the Slabodka yeshiva. He is better known by the Yiddish appellation der Alter (“the Elder”). Many of his pupils were to become major leaders of Orthodox Judaism in the USA and Eretz Yisrael.
In the environs of Slabodka close to the area of the yeshiva there was a wicked priest. This clergyman was a constant source of trouble for the Yeshiva, leveling many a libelous accusation. After countless years of harassing the Yeshiva this minister met a ignominious death.
The students jubilantly rushed to update der Alter to share with him that this menace was no longer, and life could resume worry free. The students vied with each other to be the first to inform him of the tidings.
“The priest is dead. The priest is dead” they told him.
Reb Nosson Tzvi said nothing, and his face was inexpressive, he did not even crack a slight grin. There was no evidence that he was even pleased with the news.
Some of the more inquisitive Talmidim, asked “Is the Rosh Hayeshiva displeased with the news”.
Answered the der Alter “If one celebrates and is joyous at the destruction of bad people, one unwillingly be influenced not to be unhappy when good people die”.