'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 convey me over till I come into Judah;

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

And next unto them repaired Melatiah the Gibeonite, and Jadon the Meronothite, the men of Gibeon, and of Mizpah, unto the throne of the governor on this side the river.