'River' in the Bible

Moreover I said unto the king, If it please the king, let letters be given me to the governors beyond the River, that they may let me pass through till I come unto Judah;

Then I came to the governors beyond the River, and gave them the king's letters. Now the king had sent with me captains of the army and horsemen.

And next unto them repaired Melatiah the Gibeonite, and Jadon the Meronothite, the men of Gibeon, and of Mizpah, that appertained to the throne of the governor beyond the River.