The first born from every womb is special to the Lord. The Lord formed the first man from the dust of the earth and breathed life into his nostrils. The Lord fashioned woman from the first man. (Gn.2:7, 22) Every man since the first man came into the world through his mother’s womb. (Gn.3:20) Therefore, the firstborn is holy to the Lord. So that the people remember how the Lord redeemed the first born sons of Israel in Egypt, they are to redeem the first born. The first born of the clean animals are to be sacrificed (eaten) and the first born of a beast of burden, like the donkey, who was unclean for sacrifice was to be substituted with a clean animal or his neck broken and the life of the animal wasted. This entire system of redemption and sacrifice points us to the Lord Jesus Christ, imputation, and his substitutionary atonement on the cross. “The month of Abib spans our March and April. It is the ancient name for what was later called Nisan in the Israelite calendar.” (IVP BBC OT) It is in this month that the Israelite was to remember how the Lord redeemed them and took them out of Egypt. For seven days they were to celebrate the feast of unleavened bread and their houses were to be free of leaven. This demonstrates that redeemed people should not be corrupted by the things of this world.
The Hebrew word (סוּף suph), has been translated into English, “Red Sea;” however, the literal translation of the word is “Sea of Reeds.” (NASB Strong’s (Lockman)) The most direct route from Egypt to the land of Canaan was a route called, “The way of Horus.” However, the route was a busy thoroughfare, being a sort of highway and was under constant surveillance by the Egyptian Army. (BBC) For their protection, the Lord took them on a more southern route, which would have taken the Israelites to the bitter lakes. At the time of the Exodus, there would have been a series of natural lakes between the Gulf of Suez and the Mediterranean sea: Lake Timsah, Lake Balah, and Lake Menzaleh. (IVP BBC OT)
When they departed from Egypt, the sons of Israel took the bones of Joseph with them, as he had requested of them before his death, when he prophesied that the Lord would visit them. (cf. Gn.50:24, 25) The Lord led the Israelites by a visible pillar, a cloud by day and a fire by night. The glory of the Lord went before them. This is a look forward to the incarnation of God into human flesh: “And the Word became flesh, and dwelt among us, and we saw His glory, glory as of the only begotten from the Father, full of grace and truth.” (Jn.1:14, NASB95)