Torah
Torah is a Hebrew word meaning teaching, instruction, or especially Law. It primarily refers to the first section of the Tanakh, i.e. the first five books of the Hebrew Bible.
These books are Genesis, Exodus, Leviticus, Numbers and Deuteronomy. Collectively they are also known as the Pentateuch (Greek for "five books") or Hamisha Humshei Torah (Hebrew for "the five parts of the Torah" or just Humash ["five parts"] for short).
Jews also use the word Torah, in a wider sense, to refer to the entire spectrum of authoritative Jewish religious teachings throughout history. In this sense it might include the Mishnah, the Talmud and the midrashic literature. In its widest sense, Jews use the word Torah to refer to any religious teachings perceived as being part of the oral law of rabbinic Judaism, which would include the former works, the responsa literature, the codes of Jewish law and the teachings of the rabbis.
Structure of the five books
The Torah does not contain a complete and ordered system of legislature, but rather, a general philosophical basis, and a great number of specific laws. These laws are often reminiscent of the existing customs in the ancient near east, but have important conceptual varations from them.
The book of Deuteronomy is different than the previous books; thus sometimes the first four books of the Bible are known as the Tetrateuch.
The first six books of the Bible as a unit (The Torah immediately followed by the book of Joshua) is sometimes referred to as the Hexateuch, as the book of Joshua picks up directly where Deuteronomy leaves off.
The Samaritans have their own version of the Torah, which contains many variant readings. Many of these agree with the Septuagint against the Masoretic Text, leading many scholars to believe that parts of the Samaritan text may have once been common in ancient Palestine, but rejected by the Massoretes.
Jewish view of the Torah
The Torah is the primary document of Judaism.
According to Jewish tradition, these books were given to Moses by God on Mount Sinai. This dictation included not only the "quotes" which appear in the text, but every word of the text itself, including phrases such as "And God spoke to Moses..."
The rabbis held that not only are the words giving a Divine message, but the words were also indicators of a far greater message that extends beyond them. They held that even as small a mark as a kotzo shel yod, the serif of the Hebrew letter yod (which happens to be the smallest letter), was put there by God to teach scores of lessons. This is regardless of whether that yod appears in the phrase "I am the Lord thy God," or whether it appears in that oft repeated "And God spoke unto Moses saying."
In a similar vein, Rabbi Akiva, who died in 135 A.D., is said to have learned a new law from every et in the Torah--the word et is meaningless by itself, and serves only to mark the accusative case. In other words, the Orthodox view is that "And God spoke unto Moses saying..." is no less important than the actual statement.
One kabbalistic interpretation is that the Torah constitutes one long name of God, and that it was broken up into words so that human minds can understand it. While this is effective since it accords with our human reason, it is not the only way that the text can be broken up. For Orthodox Jews, the Torah is that rush of letters and sounds that can mean so many different things.
Christianity also believes that the Torah is the word of God; however most Christians do not necessarilly hold that it was "dictated" to Moses all at once. Further, traditional Christianity holds that while the Torah's quotes from God should literally be understood as quotes from God Himself, the rest of the text is not a direct quote, but rather human words written by a prophet under divine inspiration. Thus the entire Torah is held to be a holy revelation, but not all of it is seen as a quote.
The Christian belief that Jesus is both fully human and fully divine has a very close analogy in the traditional Christian view of Scripture.
The Torah and an oral law
Rabinical Judaism holds that the Torah has been transmitted in parallel with an oral tradition. Jews point to the text of the Torah, where many words are left undefined, and many procedures mentioned without explanation or instructions; the reader is assumed to be familiar with the details from other, oral, sources.
This parallel set of material was originally trasmitted orally, and came to be known as the oral law. At the time, it was forbidden to write and publish the Oral Law, as any writing would be incomplete and subject to misinterpretation and abuse. However, after great debate, this restriction was lifted when it became apparent that it was the only way to ensure that the law could be preserved. To prevent the material from being lost, around 200 CE, Judah HaNasi took up the redaction of oral law; it was compiled into the first written work of rabbinic Judaism, the Mishnah. Over the next four centuries this body of law, legend, ethical teachings and argumentation underwent debate in both of the world's major Jewish communities (in Israel and Babylon). The commentaries on the Mishnah from both of these communities eventually came to be edited together into compilations known as the Talmud.
Most Jews follow the traditional explication of these laws that can be found in this later literature. Karaites, who reject the oral law, and adhere solely to the laws of the Torah, are a major exception.
The origin of the Torah
Modern day scholars hold that the text of the Torah appears to be redacted together from a number of earlier sources; this is known as the Documentary hypothesis, sometimes called the "JEDP" theory.