Rabbi Avram H. Herzog
Rabbi Y'hudah's Simanim
Why did R' Y'hudah assign simanim to the makkot? Is a simple mnemonic really in order for a short list as simple to remember as the mnemonic itself?
The joke is told that R' Y'hudah was being frugal; why waste ten drops of wine when one only need waste three? The irony here is that we end up spilling thirteen drops!
While one cannot know what R' Y'hudah had in mind, many suggestions have been offered. I'd like to add the following thought to the rich list.
The makkot were basically a showdown between the one true G-d and one who portrayed himself as a god. Our showdown, or ballgame, if you will, begins when Pharoh refused to "let my people go". At that point, Hashem felt the need to intervene, to prove to the world that He, and only He, is G-d. So He played the first inning and brought makkat dam upon the Egyptians. One out. But Pharoh's chartumim were able to replicate this makkah, so Pharoh wasn't moved.
Next: tz'fardeia. Two outs. This, too, Pharoh's chartumin were able to replicate, and again, Pharoh decided to face the next pitch: kinnim. Three outs. Pharoh's chartumim threw in the towel. Inning over. But Pharoh wouldn't let go of his image of being a god. Instead, he responded: "G-d, all you proved is that you are the god over dtza"ch, natural occurrences and life which emanate from the ground. (The Torah states that the kinnim came from the afar ha'aretz). But I'm still in charge of what lives and occurs on the ground level."
Time for the second inning. First pitch: arov. One out. Next: dever. Two outs. Finally: sh'chin. Inning over. Pharoh now had a chance to forfeit the game. But stubborn Pharoh had other thoughts: "All you proved, G-d, is that you are the god over dtza"ch and ada"sh, the latter which occurs and lives on the ground. But I'm still the boss of the airspace."
So G-d had no choice but to play one more inning and bring about barad, arbeh (which we are informed swarmed in via a ru'ach kadim) and choshech. Three outs. Game over? Not so fast. Pharoh, still determined to fool himself and his subjects, decided to stand up to G-d one last time: "All you proved this time G-d, is that you rule over dtza"ch, ada"sh, and now b'a"ch. So yes, you control all three individual areas which comprise the universe—below the ground level, on the ground level, and the airspace. But just as a corporation has several vice presidents, a solid structure will have a president at the helm. You may be the vice president of all three departments, but I'm the man, or god, who presides over the structure as a whole. I Pharoh, and only I, reign supreme.
Sadly, G-d now had no choice but to pitch one last ball: b'chorot. Game over. G-d had finally shown for Pharoh and all to see, that He, indeed, is the true one and only G-d!
And just as on that day the world recognized the oneness of G-d, we pray and look forward to the day when once again "yih'yeh Hashem echad ush'mo echad."