Bo

In the synagogue the Torah is read aloud in a fixed annual cycle of fifty-four weekly portions (parashiyot), one each Shabbat morning, with certain adjacent portions doubled in ordinary years so the sequence fits the calendar. Each portion is named for a distinctive word near its opening and is paired with a haftarah, a reading from the Prophets. The cycle closes and restarts on Simchat Torah. Bo ('Come', Exodus 10:1-13:16) brings the final three plagues, locusts, darkness and the death of the firstborn, and the institution of the Passover: the paschal lamb, the festival of unleavened bread, and the consecration of the firstborn, the founding rite of Israel's memory of the Exodus.

The plague of darkness, described as so thick 'it could be felt' while the Israelites had light in their dwellings (Exodus 10:21-23), is read by rabbinic commentary, drawing on a tradition in the midrash, as more than a meteorological event, some sources describing it as also concealing the deaths of Israelites unwilling to leave Egypt during the darkness so that Egyptians would not witness Israelite mortality and doubt the nation's coming deliverance. The instruction to mark doorposts with the blood of the paschal lamb, so the destroyer would 'pass over' Israelite homes during the final plague (Exodus 12:7, 12:13), gives the festival its name and is read by commentators as the Torah's founding instance of a ritual act performed for protection rather than sacrifice alone. Pharaoh's final capitulation after the death of the firstborn, urging the Israelites to leave 'in haste' (Exodus 12:33), is read as explaining the requirement of unleavened bread, since the dough had no time to rise, tying the festival's central food directly to the narrative's own pacing.

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.