In the Old Testament it is usually with the vowel points of but when the two occur together, the former is pointed , that is, with the vowels of , as in Obad, i. 1 Heb. iii. 19. The LXX, generally render it by , the vulgate by Dominus; and in this respect they have been followed by the A.V. where it is translated “The Lord.” The true pronuncation of this name, by which God was known to the Hebrews, has been entirely lost, the Jews themselves scrupulously avoiding every mention of it, and substituting in its stead one or other of the words with whose proper vowel-points it many happen to be written. This custom, which had its origin in reverence, and has almost degenerated into a superstition, was founded upon an erroneous rendering of Lev. xxiv. 16, “He that blasphemeth the name of God shall surely be put to death”; from which it was inferred that the mere utterance of the name constituted a capital offence. In the Rabbinical writings it is distinguished by various euphemistic expressions; as simply “the name”, or “the name of four letter” (the Greek tetragrammaton); “the great and terrible name”; “the peculiar name,” i.e. appropriated to God alone ; “the separate name,” i.e. either the name which is separated or removed from human knowledge, or, as some render, “the name which has been interpreted or revealed.” (Professor W.A. Wright, M.A., Smith’s Dictionary of the Bible in loco.)
This superstitious reverence for the word Jehovah must have been the origin of the Ismu ‘l-A’zam, or “exalted name,” which Muhammad is related to have said was know only to God and His prophets; but which, he said, occurs in one of three verses in the Qur’an, namely: Suratu ‘l-Baqarah ii. 256: “God! (Allah) there is no God but He (Hu) the Living One (al-Haiy), the Self-Subsisting One (al-Qaiyum)”; or, in the Suratu Ali ‘Imran iii. 1, which contains the same words; or, in the Suratu Ta Ha xx. 110: “Faces shall be humbled before the Living One (al-Haiy), the Self-Subsistent One (al-Qaiyum).
Some European scholars (see Catafago’s Arabic Dictionary) have fancied that Yahuh , or Yahovah of the Hebrews, is identical with the ejaculation of the Muslim devotee, Ya Ha, “O He!” (i.e. God). Al-Baizawi says the word Hu (better Huwa), i.e. HE (God), may be the Ismu ‘l-A’zam, or Exalted Name of the Almighty, especially as it occurs in two of the verses of the Qur’an indicated in two of the verses of the Qur’an indicated by Muhammad, namely, Surahs ii. 356, iii. i. [HUWA, GOD.]
Based on Hughes, Dictionary of Islam