The unpronounceable four-letter name of God
Reprinted with permission from The Jewish Religion: A Companion, published by Oxford University Press.
The Tetragrammaton is the four-letter name of God formed from the letters yod, hey, vav, and hey, hence YHVH in the usual English rendering. The older form JHVH is based on the rendering of yod as jod.
This name is usually translated in English as "the Lord," following the Greek translation as kyrios. All this goes back to the Jewish practice of never pronouncing the name as it is written but as Adonai, "the Lord." In printed texts the vowels of this word are placed under the letters of the Tetragrammaton. (Hence the name was read erroneously by Christians as "Jehova," a name completely unknown in the Jewish tradition.) The original pronunciation of the Tetragrammaton has been lost, owing to the strong Jewish disapproval of pronouncing the name. The pronunciation Yahveh or Yahweh is based on that used by some of the Church Fathers but there is no certainty at all in this matter. Most biblical scholars, nowadays, prefer to render it simply as YHWH or JHVH without the vowels. This name occurs 6,823 times in the present text of the Hebrew Bible.
What does the name mean? In Exodus 3:14-15 the name is associated with the idea of "being," and hence some have understood the original meaning to be "He-Who-Is," or "He who brings being into being." Generally, as [scholar Umberto] Cassuto and others have noted, the name Elohim ("God") is used in the Bible of God in His universalistic aspect, the God of the whole universe, while the Tetragrammaton is used of God in His special relationship with the people of Israel.
The Tetragrammaton in Post-Bibical Literature
The Tetragrarnrnaton is known in the rabbinic literature as Ha-Shem ("the Name") or Shem Ha-Meforash, meaning either the "special" name or the name uttered explicitly, that is, by the High Priest in the Temple. The Rabbis also refer to it as Shem Ha-Meyuhad ("the Unique Name") or as "the Four Letter Name." There is evidence that even after the change-over (between the fourth and second centuries BCE) from the old Hebrew writing to the so-called "square" script now used, the Tetragrammaton was sometimes written in the Scrolls in the old script. Although the Rabbis rejected this procedure, it is attested to as late as the fifth century CE in a fragment of Aquila's Greek translation and is mentioned by Origen as well as being found in some of the Qumran texts.
The data regarding the prohibition of pronouncing the Tetragramtnaton as it is written are complicated but the following are the main details. Philo (Life of Moses, ii. II) observes that on the front of the High Priest's miter were incised the four letters of the divine name which it is lawful only for the priests to utter in the Temple (in the priestly blessing) and for no one else, to utter anywhere.