The Torah was given to Moses, by G‑d, accompanied by an oral counterpart. The Oral Torah is just as much G‑d's word as the Written Torah.

As the years passed, the sages became concerned that the Oral Torah would be forgotten or garbled if it would not be recorded. Rabbi Judah the Prince and subsequent rabbis committed much of the Oral Law to writing. The oral traditions, combined with the rabbinical enactments, form the Talmud and much of the rest of Jewish literature.

There are many concepts which are alluded to in the Written Law but were only recorded fully in subsequent writings. This does not mean that they are any less G‑d's word. G‑d, in his unfathomable wisdom, decided that they be recorded that way.

Reincarnation is one such concept. Allow me to share just a few places where reincarnation is alluded to in the Written Torah. These are not places which shout "reincarnation" in bold letters but they do form part of a greater picture.

Ecclesiastics 1:4: "A generation departs and a generation comes." If this would refer to the normal flow of generations, a generation cannot come after the previous generation has gone. Rather this refers to the same soul(s) returning in consecutive lives.

Job 1:21: "Naked I left my mother's womb and naked I shall return there." Who comes back to their mom's womb? Enter reincarnation.

These are just a few samples. There are a number of such places scattered throughout the Torah. The bulk of what we know about reincarnation is from the Oral Torah and these are just a few places where this dynamic is evident in an almost offhand manner in the written part.

The question remains though: Reincarnation is a major theological issue. Why is such a major issue not explicitly discussed in the Written Torah?

Allow me to point out, however, that neither does the Written Torah include any information about what happens to the soul after death, heaven and hell, the nature of the soul—or even much about G‑d for that matter. The Five Books of Moses simply cannot be seen as a theological work. It is principally a practical guide, couched in story form. As for the rest of the Scriptures, even Proverbs and the Book of Job read as commentary on tacitly assumed knowledge.

It is quite apparent from reading these texts that Jewish Theology (which is all that the Kabbalah is), was meant to be transmitted orally, not in writing.

True many of the ancient cultures transmitted their theology and mystical teachings in writing, including the ancient Egyptians and Hindus. But the difference is quite simple: Ancient Egypt, India and the like were illiterate societies, save for a small number of priestly elite. When that elite wished to transmit secrets for the initiated, they committed it to writing—and such forms of writing that could only be deciphered by the initiated.

The Jews, on the other hand were uniquely a literate society. To read Hebrew, you only needed to master 22 letters—as opposed to the hundreds or even thousands of glyphs used in several ancient scripts. The common Jewish child in the ancient world was expected to be literate. Therefore, those matters that could easily be misunderstood, distorted and misused had to be transmitted orally.

This is especially true of reincarnation. As Rabbi Moshe Cordovero asserted, "Those who know do not tell and those who tell do not know." In other words, the secrets of reincarnation are meant to be held only by those who can be trusted not to spill the beans.

I hope that I've been helpful today.

Yours truly,

Rabbi Menachem Posner