Bo: arbitrary 

The plague of the first born, the centerpiece of Bo, is a paradigm of the arbitrary rule. 

The plague of death is imposed upon the firstborn, regardless of his merits, regardless of her innocence. Babies and dirty old men are subject to the same  penalty for an accident of birth order. This is a kind of fairness: every being, human or animal, is treated the same. fristborn means death, not firstborn means life.   It seems more equitable than your money or your life or the concentration camp  selection. Salvation comes from joining the Hebrews in their matzo and lamb's blood smearing ritual.

The consequences of this plague include a transfer of authority away from Pharaoh to Moshe

 In Chapter 11, Moshe says to Pharaoh:

וְיָרְדוּ כָל-עֲבָדֶיךָ אֵלֶּה אֵלַי וְהִשְׁתַּחֲווּ-לִי לֵאמֹר, צֵא אַתָּה וְכָל-הָעָם אֲשֶׁר-בְּרַגְלֶיךָ, וְאַחֲרֵי-כֵן, אֵצֵא; וַיֵּצֵא מֵעִם-פַּרְעֹה, בָּחֳרִי-אָף.  {ס} 8 And all these thy servants shall come down unto me, and bow down unto me, saying: Get thee out, and all the people that follow thee; and after that I will go out.' And he went out from Pharaoh in hot anger. {S}

 The release of the Hebrews has become the popular idea of expulsion of the Jews.  Egypt must be Judenrein! The Hebrews bring a curse upon the land.  

Here is survivor guilt,  survivor glory and  survivor debt. Escape from the arbitrary, worn as a sign on the arm and head. 

Every person is special in her own arbitrary way.