Tetragrammaton

The Tetragrammaton, literally means the four-letter word. The word in question is the Hebrew word יהוה spelled using the Hebrew alphabet: yodh י heh ה waw ו heh ה. (Note that Hebrew text is written from right to left). This is the ineffable name of God in Hebrew, and is so holy that observant Jewish people read it as "hashem" which means "the name".

A reading from the Tanakh when Moses was faced with the burning bush on Mount Sinai, translates the Tetragrammaton as I am that I am. Because of the strictures in Judaism, the pronunciation is controversial.

See Yahweh and The name of God in Judaism. See also four-letter word.