The fact that God took possession of the Levites as his firstborn does not mean that the rest of Israel did not belong to him, or that God did not care about the rest of the nation. As God's firstborn the tribe of Levi was given the special responsibility of caring for the needs of the rest of Israel. God’s choice of the Levites did not diminish but affirmed his love for the rest of Israel.
12 Voici, j'ai pris les Lévites du milieu des enfants d'Israël, à la place de tous les premiers-nés, des premiers-nés des enfants d'Israël; et les Lévites m'appartiendront.