The Oral Torah Rabbinic tradition holds that Moses learned the whole Torah while he lived on Mount Sinai for 40 days and nights and both the Oral and the written Torah were transmitted in parallel with each other. Where the Torah leaves words and concepts undefined, and mentions procedures without explanation or instructions, the reader is required to seek out the missing details from supplemental sources known as the Oral Law or Oral Torah. Some of the Torah's most prominent commandments needing further explanation are: Tefillin: As indicated in Deuteronomy 6:8 among other places, tefillin are to be placed on the arm and on the head between the eyes. However, there are no details provided regarding what tefillin are or how they are to be constructed. Kashrut: As indicated in Exodus 23:19 among other places, a young goat may not be boiled in its mother's milk. In addition to numerous other problems with understanding the ambiguous nature of this law, there are no vowelization characters in the Torah; they are provided by the oral tradition. This is particularly relevant to this law, as the Hebrew word for milk (חלב) is identical to the word for animal fat when vowels are absent. Without the oral tradition, it is not known whether the violation is in mixing meat with milk or with fat. Shabbat laws: With the severity of Sabbath violation, namely the death penalty, one would assume that direction would be provided as to how exactly such a serious and core commandment should be upheld. However, most information regarding the rules and traditions of Shabbat are dictated in the Talmud and other books deriving from Jewish oral law. According to classical rabbinic texts this parallel set of material was originally transmitted to Moses at Sinai, and then from Moses to Israel. At that 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 exile, dispersion, and persecution, this tradition was lifted when it became apparent that in writing was the only way to ensure that the Oral Law could be preserved. After many years of effort by a great number of tannaim, the oral tradition was written down around 200 CE by Rabbi Judah haNasi, who took up the compilation of a nominally written version of the Oral Law, the Mishnah (Hebrew: משנה). Other oral traditions