Actually, when we examine the connection between Numbers and the books that precede it, we discover that it is not actually a continuation of Leviticus, but of Exodus. The book of Exodus ends with the description of the cloud that hangs over the Tabernacle and with the regulations regarding travel and camping for the Children of Israel during their desert journey. From here, there is a split in the narrative: one goes on to the book of Leviticus and deals with the Tabernacle and related issues; the other continues on to Numbers that describes the journey in the desert and the internal and external hardships this entailed.
However, there are several parallels between Leviticus and Numbers that teach us something about the content of both books. One deals with the holiness of the Tabernacle and the priesthood, while the other deals with the holiness of the camp, the nation, and the family.
Thus, for example, if in the book of Leviticus we read about priests sacrificing offerings, in the book of Numbers there is a focus on the sacrifices brought by the leaders of the tribes who dedicated the Tabernacle with their offerings. If in Leviticus we read about stealing as an offense against G-d demanding atonement, in Numbers we learn about stealing from a ?ger? (stranger) as an offense against someone without rights. Leviticus provides an in-depth description of the holiness of priests and the restrictions incumbent upon them, while Numbers tells us about the ?sotah? that deals with the holiness of the Jewish family. We can also compare the High Priest and his work which is described in detail in Leviticus with the monastic ?nazir? described in Numbers, who can come from any tribe and any part of the nation and is compared in many ways to the High Priest.
In Numbers, we take on a different outlook from the one we had in Leviticus. Until now we read and learned about the Tabernacle and the priests ? a restricted space and specific people whose spiritual level and role served as a beacon for the entire nation. But from here on we speak about the nation itself and aspire that the holiness will be expressed within the family, not just in the temple; in interpersonal relationships, not only in worship of G-d; in the army and not just in the synagogues. Judaism aspires not only to elevate a limited number of places and people and make them holy, but for those sacred places and people to spread that holiness to the entire nation.
We find this idea expressed in the commandment of tzitzit (fringed garment) that also appears in Numbers. In all cultures, clothing is first and foremost a way to cover the body, protect it from the cold and the heat, and a mode of decoration. It also categorizes. So, for example, there is special clothing for soldiers, doctors, judges, etc. In the previous books we read about the special clothing worn by the priests during their work in the Temple, clothing that expressed their special status.
But the commandment of tzitzit is for every Jew, and it teaches us that every Jew is part of a framework of identity and belonging that carries a purpose and a role. A plain item of clothing becomes characteristic of Jews, carrying cultural and spiritual significance. This Jewish item of clothing does not belong to any specific level of society. It teaches us that the entire nation is holy, carries a spiritual message, has a unique culture that aspires to transcend, and strives to elevate all of humanity toward holiness and purity, toward a life of G-d worship and moral spirituality.