Exodus 6:3 and I appeared unto Abraham, unto Isaac, and unto Jacob, as God Almighty, but by My name Yud-Kay-Vav-Kay* I made Me not known to them. [*"Yud-Kay-Vav-Kay" is the Yiddish circumlocution for the spelling of the tetragrammaton. In this verse, the original Jewish Publication Society text uses the Hebrew letters that correspond to the actual spelling of the name.] (JPS)