Bo is where the Torah first legislates a festival: the Passover, with its lamb, its unleavened bread and its charge to 'tell your child' the story, establishing the pattern of ritual memory that shapes Jewish time. The command to mark the doorposts and to sanctify the firstborn is woven into later observance, including the tefillin passages drawn from this portion, tying the Exodus to daily practice.
The command to 'tell your child' the Exodus story (Exodus 13:8), repeated in varied form across the Torah's festival legislation, became the structural basis for the Passover seder's question-and-answer format, and rabbinic literature developed from the Torah's own varied phrasing of the instruction the seder's traditional framework of four children distinguished by how they ask, or fail to ask, about the meaning of the ritual. The consecration of the firstborn, both of Israel's own children and of their livestock, to God (Exodus 13:2, 13:11-13) is read by commentators as a direct consequence of the tenth plague, so that the ongoing obligation, later redeemed for children through the ceremony of pidyon haben, keeps the memory of that specific night embedded in an otherwise unrelated area of Israelite family law. The passages instructing that this be a sign on the hand and a reminder between the eyes (Exodus 13:9, 13:16) are, alongside a parallel passage in Vaetchanan, among the four Torah sections rabbinic tradition inscribes in tefillin, physically binding this portion's narrative to daily prayer.