Time to start thinking about Pesach, and what better place to start than Parshas Shmini. At the very end of the parsha the Torah juxtaposes the prohibition of eating sheratzim with the reason, "Ki ani Hashem hama'aleh eschem mei'Eretz Mitzrayim..." (11:45) Rashi explains that the Torah uses the term "ma'aseh" here instead of the usual "hotzi" to indicate that leaving Egypt elevated us. Chazal teach that had the only gain from the exodus from Egypt been our acceptance of this command to not eat bugs, that itself would be an elevation, a privilidge and mark of distinction for the Jewish people.
R' Simcha Zisel of Kelm (in case you are keeping score, that's a Slabodka, Navardok, and now a Kelm vort all in one week) asks: If Hashem wanted to elevate the Jewish people by commanding them to not eat bugs, why could he not give that command while they remained in Egypt? Why did it necessitate yetziyas Mitzrayim -- how are these two ideas related?
Without understanding R' Simcha Zisel's answer we don't even get to square one of understanding what Pesach is all about. Hashem could give Torah and mitzvos at any time, in any place, to any people. The reason Torah was given when it was, to whom it was, is not because that's when Hashem had a free day on his calendar, but rather because that's when we as a people were ready to receive it. That readiness was a direct product of yetziyas Mitzrayim. Leaving Egypt was not just a physical escape from bondage, but was a transformation of our souls.
Even a mitzvah so basic as not eating bugs could not be given while we remained in Egypt. It required that our neshomos first experience the exodus from Egypt and that spiritual transformation from avdus to cheirus.