Several chapters at the beginning of Sefer Sh’mot deal with the ten plagues.
Time after time the amazing things which God orchestrated in Egypt seemed to fall short because the Egyptian sorcerers worked out how to duplicate them (Ex. 8:3). The sorcerers, for example, turned water into blood and made frogs rise up from the sea.
We wonder why it was worth God’s while to produce effects which the sorcerers could duplicate.
One answer (given by Ibn Ezra: Ex. 7:22) is that what the Egyptian sorcerers did was not an exact copy of the Divine acts. For example, the sorcerers could not turn flowing water into blood but could only work their magic on static water, though this was already quite an achievement.
Possibly the passage is telling us that there are times when good and evil can both produce effects, times when the wicked son of the Haggadah can work out how to do clever things, and people have to know the differences between good and evil, and their implications.
Aaron and not Moses
Aaron, not Moses, presided over the beginning of the plagues. It was Aaron who brought about the plague that affected the waters of the Nile (Ex. 7:19), and only thereafter did he address the other waters of Egypt.
Why did his brother Moses not bring about the first plague?
The sages, followed by Rashi, say that it would not have been right for Moses to harm the waters of the Nile, since it was those waters that had protected his cradle when he was a baby.
The way the sequence of the plagues proceeded illustrated the principle of hakkarat ha-tov, showing gratitude for a favour.
The Aaron and Moses story teaches us the ethical principle of thankfulness.
Revealing the Divine Name
The sidra begins with HaShem telling Moses His personal four-letter Name (Ex. 6:2). God states that until now the name by which He had made Himself known was the Hebrew title E-l Sha-ddai, which means "powerful Deity". The four-letter Name spelt Yod-Hey-Vav-Hey was not yet formally revealed to the people.
What was special about that four-letter Name that its introduction had to be delayed?
The Name is explained by rabbinic tradition as "God of loving mercy". Until now the nation had mostly seen the immense creative power and strength of the Almighty but now it was time for them to see His love, forgiveness and concern manifested in their midst.
The earlier chapters (e.g. the Akedah, Gen. 22) sometimes did use the four-letter Name but that is because ein mukdam um’uchar baTorah, the narrative is not always strictly chronological.