Buried in the notes below in the outline from my sermon this last week, is the observation that the priesthood is based on the concept of the “firstborn son.” Israel is called Yahweh’s firstborn son and because Pharaoh refuses to release him, Yahweh strikes down Pharaoh’s firstborn son. Based on this tenth plague and the Passover event, God claims all of the firstborn males of both man and animal in all Israel. They are all to be consecrated, made holy to him, because he passed over them and slayed the firstborn of Egypt. Later, in Numbers, God explains that instead of taking the firstborn of Israel, he is going to take the tribe of Levi to be the ministers of his house. Thus the priesthood is based upon the consecration of the firstborn of Israel which (in turn) is based upon the fact that Israel as a nation is Yahweh’s firstborn son.
This helps make sense of the fact that Yahweh calls Israel a kingdom of priests and a holy nation in Exodus 19. Since the whole nation is God’s firstborn son, the whole nation is a priestly people, a holy nation.
But I think this “firstborn” business actually reveals a great deal about what it means to be a priestly people. In the ancient world and in Scripture, the firstborn son was shown a great deal of attention, care, and finally bestowed with a double portion of his father’s inheritance. So often, we just assume that ancient people were weird. “They just did those sorts of things,” and we think nothing more about it. Or we say, “yeah, in the old days it was important to keep up the family name,” but that’s only half true.
Actually, the idea was that the firstborn son was the one that was given the task of carrying on the mission of the father’s house. The firstborn son was shown so much attention, so much care because it rested upon his shoulders to continue what the father had started and what his father before him had done, and his father before him, and so on. The reason the firstborn son was shown such attention and care is not because God sanctioned favoritism, but because every wise father, boss, pastor, coach, etc. knows that in order to pass on certain skills, abilities, and priorities, time must be spent with the heir. It was never meant to be a sort of favoritism; it was meant to be the opportunity for the father to pass on his mission and work to the son. The firstborn son was bequeathed the great responsibility of keeping up and advancing the house of his father. And the double portion of inheritance was the material means of carrying that mission out, not to mention caring for the father and mother in their old age.
Thus when it came to Israel being called Yahweh’s firstborn, this was the immediate call of Israel to begin training under Yahweh’s care, to begin training to join the Father’s mission and to take up that mantle on behalf of the Father. Thus, for Pharaoh to deny Yahweh’s request to allow his son freedom to serve him, was for Pharaoh to threaten the house of Yahweh. It was not merely an assault on Israel but an assault on Yahweh, the Father of Israel. It was to denounce and dishonor the mission of Yahweh in the world.
For Israel to be called out of Egypt as the firstborn son of Yahweh, was for Israel to be called up for training in the house of Yahweh. And this is exactly what the book of Exodus is about. Following the giving of the law, Exodus 25 begins the instructions for building God’s house. The book of Exodus is about what it means to be the firstborn son, and in particular, the firstborn son of Yahweh. But this also means that the call to be God’s firstborn son was not divine favoritism; it was God’s way of showing the world what his mission is in the world. The firstborn son was no better than the other sons (other nations), but in order for the Father to pass that mission on successfully, it was necessary for one son (Israel) to be shown that special care, attention, etc., so that the firstborn son might have all the resources necessary to take up the responsibility of carrying on the mission of his father’s house in and for the world.
From this angle, it is clear what priests are called to do. To be a priest or to be a priestly people is to be trained in the ways of the household of the father in order that when the son comes of age, he might take on the mission of the father and work in the world on behalf of the Father. Of course for Israel this meant that He (Israel) was called to a ministry of reconciliation with the nations. Israel was called to teach the nations, serve the nations, and eventually, call the nations to join Israel at the table in their Father’s house.