Every firstborn son belongs to God and must be redeemed. This law is repeated several times in the Pentateuch. For example:
11 “This is what you must do when the Lord fulfills the promise he swore to you and to your ancestors. When he gives you the land where the Canaanites now live, 12 you must present all firstborn sons and firstborn male animals to the Lord, for they belong to him. 13 A firstborn donkey may be bought back from the Lord by presenting a lamb or young goat in its place. But if you do not buy it back, you must break its neck. However, you must buy back every firstborn son.
15 “The firstborn of every mother, whether human or animal, that is offered to the Lord will be yours. But you must always redeem your firstborn sons and the firstborn of ceremonially unclean animals. 16 Redeem them when they are one month old. The redemption price is five pieces of silver ..."
(see more Bible verses here).
I am very much aware that the sacrifice of Isaac story (Gen 22) is commonly seen as Abraham's test of faith, prefiguration of God's sacrifice of His Son, and prefiguration of the obedience of Isaac/Jesus. But does the Bible ever mention that the sacrifice of Isaac is also a prefiguration of this law?
What got me thinking is because of the following parallels:
- Isaac is God's fulfillment of his promise to Abraham (see Ex 13:11)
- Isaac obviously belongs to God since it's only by miracle that Abraham had a descendant (Ex 13:12)
- Isaac is the firstborn of Sarah; Ishmael didn't count since he's of a different mother (Num 18:15)
- Although God provided the lamb to replace Isaac, it can still be seen as redemption (Ex 13:13)