When God smites all the firstborn among the Egyptians, he sanctifies the firstborn of the Jews, assigning them the role of serving God in the Tabernacle. However, he soon replaces them with the Levites, as we read in the Bible: "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; 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" (Numbers 3:12-13).
The Torah explicitly tells us that the Levites replace the firstborn without giving the explicit reason for the substitution. Why are God's servants suddenly replaced? In a midrash, the classic rabbinic authorities explain: "Initially, the firstborn served God in the Tabernacle; however, because they committed the sin of the Golden Calf, God chose the Levites to replace them, because the Levites had not been party to that sin" (Numbers Rabbah, section 3).
At that difficult hour when the Israelites declared "These be thy gods" (Exodus 32:8), the tribe of Levi remained loyal to God. When Moses cried out, "Who is on the Lord's side?" - the entire tribe responded to his call: "And all the sons of Levi gathered themselves together unto him" (Exod. 32:26). That is why God says of the Levites: "And I, behold, I have taken the Levites from among the children of Israel instead of all the firstborn."
The verse "At that time the Lord separated the tribe of Levi, to bear the ark of the covenant of the Lord, to stand before the Lord to minister unto him, and to bless in his name, unto this day" (Deuteronomy 10:8) is interpreted by Rashi in the following manner: "`At that time': Less than a year from the time of the Exodus from Egypt, you [that is, the firstborn] erred, committing the sin of the Golden Calf; however, the Tribe of Levi did not follow your example. That is why God has separated them from you."
In the Book of Ezekiel, we read: "But I said unto their children in the wilderness: Walk ye not in the statutes of your fathers, neither observe their judgments, nor defile yourselves with their idols ... Notwithstanding the children rebelled against me: They walked not in my statutes, neither kept my judgments to do them, which if a man do, he shall even live in them ... And I polluted them in their own gifts, in that they caused to pass through the fire all that openeth the womb, that I might make them desolate, to the end that they might know that I am the Lord" (Ezekiel 20:18-26).
Selected and sanctified
As we can read in these verses, the firstborn were sanctified from birth, their holiness stemming from the fact that their lives were spared (at the time of the plague of the firstborn in Egypt). However, they lose their birthright through their commission of the sin of the Golden Calf and through their evil deeds. The Levites, who were not sanctified from birth, for whom no miracle was performed but who chose not to commit the sin of the Golden Calf, are selected and sanctified by God.
If we are granted sanctity and if we prove unworthy of it, we forfeit it, whereas the sanctity that we gain through our deeds and through our conscious choices is a lasting sanctification.
The Italian-Jewish exegetist Sforno explains that we confess this truth whenever we remove tithes from our home, as we are commanded to do by the Torah: "When thou hast made an end of tithing all the tithes of thine increase the third year, which is the year of tithing, and hast given it unto the Levite, the stranger, the fatherless and the widow, that they may eat within thy gates, and be filled. Then thou shalt say before the Lord thy God, I have brought away the hallowed things out of mine house, and also have given them unto the Levite, and unto the stranger, to the fatherless and to the widow, according to all thy commandments which thou hast commanded me: I have not transgressed thy commandments, neither have I forgotten them" (Deut. 26:12-13). Sforno comments: "Because of our sins and because of the sins of our fathers, the firstborn, who were originally supposed to receive the voluntary offerings (trumot) and the tithes, forfeit the privilege of serving God."
Or, in other words: Had they not sinned, the firstborn would have been sanctified to serve God in the Tabernacle and there would have been no need for us to remove tithes from our home. However, the Israelites, including the firstborn, commit the sin of the Golden Calf, with only one tribe, the Levites, remaining obedient to God. Thus, God chooses the Levites to replace the firstborn. Sanctity is now no longer present in every home and tribe. Instead, the Israelites must remove the tithes from their home and give them to only one tribe - the Levites.
This is one of the things that Korah challenges when he rebels against Moses. Korah claims that Moses, without consulting anyone, replaced the firstborn with his own tribe, the Levites. As Nachmanides writes: "To gain the Israelites' support, Korah challenges the status of the Levites, demanding the reinstatement of the firstborn as God's servants in the Tabernacle."
We learn a similar lesson from the Book of Genesis, where the firstborn always loses to the younger brother: Esau, the firstborn, forfeits his birthright to Jacob, the naive and righteous younger son. Because of his sinful behavior, Reuben forfeits his birthright to Judah and Joseph. We thus learn that status is primarily dependent on our deeds and our choices, not on birthright.
Maimonides offers an innovative insight: The firstborn lose their sanctified status because of their sinful behavior, while the Levites are granted sanctification for their righteous conduct. A similar principle applies to future generations. Even those who are not Levites but who wish to be sanctified to serve God, can achieve the same sanctification that was granted to the Levites. As Maimonides says (in the last segment of his laws governing shmitta, the sabbatical year): "This applies not only to the Levites but to all those whose heart and brain lead them to stand before God, to serve him, to be his servants, to have full knowledge of God's existence, to walk a righteous path ... and to remove from their necks the yoke of empty mortal thoughts. These individuals can attain eternal sanctification with God's grace and protection and can attain in this world the same wonderful gift granted to the high priests and Levites, as King David writes: `The Lord is the portion of mine inheritance and of my cup: thou maintainest my lot' [Psalms 16:5]."