'O God' in the Bible

For this cause, hast thou magnified thyself, O Yahweh Elohim, - for there is none like unto, thee, yea there is no God besides thee, according to all that we have heard with our ears.

And it came to pass, when David reached the summit, where he bowed himself down unto God, that lo! there met him, Hushai the Archite, his tunic rent, and earth upon his head.