Just what basis was originally assigned for discontinuing the use of the name is not definitely known.Some hold that the name was viewed as being too sacred for imperfect lips to speak.The time did come, however, when in reading the Hebrew Scriptures in the original language, the Jewish reader substituted either (God) rather than pronounce the divine name represented by the Tetragrammaton.This is seen from the fact that when vowel pointing came into use in the second half of the first millennium C.(Isa 64:2) The name was in fact known and used by pagan nations both in pre-Common Era times and in the early centuries of the Common Era. If so, this was poor reasoning, as it is obvious that the more mysterious the name became through disuse the more it would suit the purposes of practicers of magic. 326) It regularly presents the Tetragrammaton, written in square Hebrew characters, in each case of its appearance in the Hebrew text being translated. Josephus, a Jewish historian from a priestly family, when recounting God’s revelation to Moses at the site of the burning bush, says: “Then God revealed to him His name, which ere then had not come to men’s ears, and of which I am forbidden to speak.” (II, 276 [xii, 4]) Josephus’ statement, however, besides being inaccurate as to knowledge of the divine name prior to Moses, is vague and does not clearly reveal just what the general attitude current in the first century was as to pronouncing or using the divine name.Just as the reason or reasons originally advanced for discontinuing the use of the divine name are uncertain, so, too, there is much uncertainty as to when this superstitious view really took hold. This theory, however, is based on a supposed reduction in the use of the name by the later writers of the Hebrew Scriptures, a view that does not hold up under examination. This papyrus is dated by scholars as being from the first century B. E., and thus it was written four or five centuries earlier than the manuscripts mentioned previously. The Jewish Mishnah, a collection of rabbinic teachings and traditions, is somewhat more explicit.
They point out that the abbreviated form of the name is Yah (Jah in the Latinized form), as at Psalm 89:8 and in the expression found in the Hebrew spelling of the names Jehoshaphat, Joshaphat, Shephatiah, and others, can all be derived from Yahweh.
Vowel points did not come into use in Hebrew until the second half of the first millennium C. (See HEBREW, II [Hebrew Alphabet and Script].) Furthermore, because of a religious superstition that had begun centuries earlier, the vowel pointing found in Hebrew manuscripts does not provide the key for determining which vowels should appear in the divine name.
At some point a superstitious idea arose among the Jews that it was wrong even to pronounce the divine name (represented by the Tetragrammaton).
The Hebrew consonants of the name are therefore known.
The question is, Which vowels are to be combined with those consonants?