The ba'alei mussar focus focus on the reaction to Moshe's warning in last week's parsha that "ha'yarei es dvar Hashem," the person who fears Hashem, should take his animals in from the field so they are not smitten by the hail of barad. By this point the Mitzrim had seen six makkos come exactly as predicted by Moshe and there was little to lose by taking the animals in just in case. And yet, there were Mitzrim who left their animals out and suffered the consequences. It was not a lack of knowledge or lack of evidence that prevented the Mitzrim from accepting Moshe's warning -- by this point, having gone 6 for 6, Moshe's warning was entirely credible and worthy of any rational person's consideration. Rather, it was simple stubbornness that prevented them from listening. Lack of emunah in this case, and according to the ba'alei mussar this is symptomatic of all cases, was the irrational response rather than the reasonable one.
The lesson I take away is more of a positive one. I don't know about you, but if someone described me as a "yarei es dvar Hashem" I would take it as a pretty big compliment. What did it take to be a Mitzri who is "yarei dvar Hashem?" Apparently all it took was giving just enough credence to Moshe's warning (after Moshe had already proven himself multiple times over) to hedge one's bets by bringing the animals into the barn rather than risk their loss. Such a little thing to do! But apparently because there is such a big yetzer ha'ra to remain stubbon in spite of all the evidence, to remain stubborn even when the risk of being wrong might bring disaster and the upside if right is so great, that even for such a small thing one deserves to be called "yarei es dvar Hashem."