Jehovah

(the Existing One) (Exod 3:14) - one of the great and holy names of God, signifying the self-existence, eternity, and immutability of God's being: the name of Him who was, is, and shall be, and who said of Himself, 'I the LORD, the first, and with the last; I am he' (Isa 41:4), and, 'I am Alpha and Omega, the first and the last' (Rev 1:11 in the source's citation). Out of reverence for this holy name, the Jews in ancient times regarded it as too fearful to pronounce and substituted either Adonai or Elohim, 'Lord.' Furthermore, according to Jewish tradition, the word Jehovah was pronounced only by the high priest, and that once each year in the Holy of Holies.

'I AM THAT I AM,' God said to Moses when sending him to the children of Israel; 'thus shalt thou say unto the children of Israel, I AM hath sent me unto you' (Exod 3:14). 'This is my name for ever, and this is my memorial unto all generations' (v. 15). The name Jehovah nevertheless occurs in full or abbreviated form in many proper names in the sacred books, joined to them either at the beginning or the end. Such names belong to various persons and, naturally enough, occur much more often after Moses' time than before it.