'Tigris' in the Bible

The name of the third river is the Tigris, which runs east of Assyria. And the fourth river is the Euphrates.

Then the servant took ten of his master’s camels, and set out, taking some of his master’s good things with him; so he got up and journeyed to Mesopotamia [between the Tigris and the Euphrates Rivers], to the city of Nahor [the home of Abraham’s brother].