The words of Moreinu HaRav Eliezer Berland shlit”a on Parshat Bo:
The Kol Simchah asks: Why doesn’t Hashem say to Moshe here which plague to inflict? He says to him, “Come to Pharaoh.” He doesn’t tell him which plague: with blood, frogs, lice, a swarm of wild beasts, pestilence, boils, hail. In every plague, He tells him, “Now there will be blood, now there will be frogs, now there will be lice, now there will be a swarm of wild beasts, now there will be boils, pestilence, hail…” Here, He doesn’t tell him which plague. “Hashem said to Moshe, ‘Come to Pharaoh.’” He doesn’t tell him which plague, “For I have made his heart and the heart of his servants stubborn…that I made a mockery of Egypt and My signs that I placed among them.” Why doesn’t he tell him which plague He is going to give him. So really the “Kol Simchah” – Rabbi Simcha Bunim of Peshischa — says here that the Kadosh Baruch Hu wanted that for one plague, the Tzaddik himself would choose. One plague would be the choice of the Tzaddik, that Moshe himself would choose. Hashem said to Moshe, “You yourself decide which plague to give him. You figure out which plague is the most fitting to give him.” Whichever plague he would desire – “You choose which plague.”
The “Yetev Lev,” the father of the “Kedushat Yom Tov,” the grandfather of the previous Satmar Rebbe who passed away, brings here in Parshat Bo from Rabbi Shimshon of Ostropli: It is written, “Come to Pharaoh so that I may place these signs of Mine within him.” He says to him “within him,” because in the name of a person is alluded all that needs to happen to him. Hashem said to Moshe: You will find within Pharaoh, the “within him” of Pharaoh, the plague that he needs to receive. Because everything that happens to a person during his lifetime is alluded to in his name. Therefore, when a person ascends on high, they ask him what his name is. They say to him: “You didn’t use your name. You had needed to act according to your name. You would have attained everything in the world.” The name of a person alludes to him everything that he needs to go through, everything that he needs to do, everything that he needs to learn. Everything is alluded to in the name of a person.
So Hashem Yitbarach says to Moshe, “Come to Pharaoh, for I have made his heart and the heart of his servants stubborn, so that I may place these signs of Mine within him.” Then Rabbi Shimshon of Ostropoli says, “These signs (otiot – which also means “letters”) of mine within him” – within him mamash, within his name! Put them in the letters of his name – there the plague of locusts is alluded to. How is the plague of locusts alluded to in the letters of “Pharaoh”? So that “I may place these signs/letters of Mine within him” – within the letters of “within him (bekirbo),” in “Pharaoh,” the plague which he needs to receive is alluded to. The “Yetev Lev” asks: “That I have placed within these letters, these hidden words which come through the power of relating these two matters, they will attain faith and know with knowledge, not with seeing, that I, Hashem, am concealed and hidden. I, I am the Concealed and Hidden One.”
“So that I may place these signs/letters within him” – within the word “Pharaoh.” Put the word “come (בא)” in the place of פע of “Pharaoh (פרעה)”. Switch the Peh with Bet, and switch the Ayin with Alef. Then it comes out “Arbeh (ארבה) – locusts.” The main thing is that the plague is what the Tzaddik chooses. The true plague which Pharaoh received was the plague which Moshe chose according to the allusions which Hashem gave to him. Hashem said, “I will not tell you which plague…Come (בא) to Pharaoh…so that you may relate in the ears of your son and your son’s son how I made a mockery of Egypt.”
(The shiur went through editing, and if there is an error, it should not be attributed, God forbid, to Moreinu HaRav shlit”a, rather to the writer.)