The firstborn of all clean, male animals were God's, and they were to be sacrificed to Him. Amazingly, these animals appear to represent the Egyptian firstborn, and thus represent a sin offering for us. The Israelites were to redeem or buy back the firstborn of their children by offering a lamb in its place. God's immediate answer to the curious Israelite child's question ties this act to the deliverance from Egypt, emphasizing that by strength of hand the Lord brought them out of the house of bondage.

God declared that He would strike all the firstborn in the land of Egypt, both man and beast, executing judgment against the gods of Egypt while passing over the houses marked by the blood of the lamb. This judgment fell from the firstborn of Pharaoh on his throne to the firstborn of the female servant at the handmill and all the firstborn of the animals. The threat extended to every firstborn within Egypt's borders, placing even the Israelite firstborn under the same sentence of death unless the blood served as the required sign. God had earlier announced to Pharaoh that Israel was His son, His firstborn, and that refusal to release this son would result in the death of Pharaoh's own firstborn. The Passover instructions therefore positioned the blood on the doorposts as the means by which Israelite households were exempted from the destroyer. With the blood, life remained; without it, the Israelite firstborn would have shared the fate of Egypt's firstborn. This event accomplished the redemption of Israel as God's firstborn nation, purchasing the people from Pharaoh's legal claim and delivering each family's firstborn. The same principle later required a lamb to redeem both unclean animals and human sons, tying the original Passover directly to the ongoing redemption of the firstborn. The striking of Egypt's firstborn thus served as the decisive act that freed God's firstborn while demonstrating His covenant faithfulness to Abraham, Isaac, and Jacob rather than any provision of atonement for sin.