Jah Jah or Jah is a name for God. It ist the shortform of Jahwe. The Rastafari movement uses this expression often in their songs, there is a Bob Marley Titel "Jah is mighty" and the Reggae Artist Gentleman sings "jah jah mad us and he will see us true". The Rastafari see Haile Selassie of Ethiopia as the incarnation of God and they call him Jah - Jah Rastafari. And so menans Hallelujah: "praise jah".
