The night of the exodus came. After the lengthy plagues, speeches, and extended instructions for the Passover and Feast of Unleavened Bread observances, the exit began. The second half of Exodus 12 continues to braid together the three themes of the Passover lamb, the death/life of the firstborn, and the necessity of bread without yeast. The narrative describing the beginning of the actual exit from Egypt forms the central panel (D) of the chiastic structure we saw in the previous chapter:

C First Passover instruction to the people (vv. 21–27)
D First historical Passover-unleavened bread event: The exodus (vv. 28–42)
C′ Perpetual Passover ordinance to Moses (vv. 43–51)

The last part of Exodus 12 (containing C′) mirrors the former material (C) about the Passover.

12:28–42 The people kept…