'River' in the Bible

And I say to the king, 'If to the king it be good, letters let be given to me for the governors beyond the River, that they let me pass over till that I come in unto Judah:

And I come in unto the governors beyond the River, and give to them the letters of the king; and the king sendeth with me heads of a force, and horsemen;

And by their hand hath Melatiah the Gibeonite strengthened, and Jadon the Meronothite, men of Gibeon and of Mizpah, to the throne of the governor beyond the River.