In each and every generation, a person is obligated to see himself as if he left Egypt, as it is stated (Exodus 13:8); "For the sake of this, did the Lord do [this] for me in my going out of Egypt." Not only our ancestors did the Holy One, blessed be He, redeem, but rather also us [together] with them did he redeem, as it is stated (Deuteronomy 6:23); "And He took us out from there, in order to bring us in, to give us the land which He swore unto our fathers."