When God chooses to do anything, His choice involves saying yes to something and no to something else. Here, the choice seems arbitrary to our thinking. It could as well have been firstborn females, or last born, as far as we can jusdge.
The Bible is full of God’s choice. God chose Israel as a “firstborn” (Ex 4:22). Then God spared the firstborn of Israel in the tenth plague (Exod 13:2). Then God claimed special ownership of all firstborn males. In the New Testament, God’s choice is called divine election. Theologians have named it predestination, and the arguments pro and con question the fairness of an all-powerful being choosing some and not others for special blessing, with no appeal from His choice.
Yes God chooses, from the start of history until the end. In every case, these choices remand is that: (1) God is sovereign and His will surpreme and nonnegotiable; (2) God is love, and His choices are grounded in His character and lead to His promise of eternal salvation; (3) God is not passive bystander but involved, active, and shepherdlike.
In the case of firstborn males, the choice puts a symbolic imprint on every family. No parent can claim exclusive, omnipotent control over a family. In even the most intimate human relationship, God has a prior claim. Even Jesus’ parents observed the claim by presenting their firstborn son at the temple. The intimacy of His claim reminds us of God’s intensely personal love for His people. Here is a God whose chief point of interest is the person. How unlike all other gods, figment of human creativity that purport to enjoy vast temples and collected riches. God’s choice of the firstborn male is itself a guide to our own most important choice-that of believing in the firstborn Son of God, Jesus.
NUMBERS 3:12-13 – 12: And I, behold, I have taken the Levites from among the children of Israel instead of all the firstborn that openeth the matrix among the children of israel: therefore the Levites shall be mine;
13: Because all the firstborn are mine; for on the day that I smote all the firstborn in the land of Egypt I hallowed unto me all the firstborn in Israel, both man and beast: mine shall they be: I am the LORD.