“The fifteenth reading from the Torah is named Bo (בוא), which means “Come.” The title comes from the first words of the first verse of the reading, which say, “Then the LORD said to Moses, ‘[Come] to Pharaoh, for I have hardened his heart” (Exodus 10:1). The portion begins by concluding the narrative of the ten plagues, the tenth of which is the slaying of the firstborn. To avoid the plague, the Israelites are given the instructions for the Passover sacrifice and the laws of the Feast of Unleavened Bread. Pharaoh finally consents to let Israel go, and they leave Egypt.” (First Fruits of Zion)
