Ezra 4:16

4:16 We therefore are informing the king that if this city is rebuilt and its walls are completed, you will not retain control of this portion of Trans-Euphrates.”

Genesis 15:18

15:18 That day the Lord made a covenant with Abram: “To your descendants I give this land, from the river of Egypt to the great river, the Euphrates River –

Joshua 1:3-4

1:3 I am handing over to you every place you set foot, as I promised Moses. 1:4 Your territory will extend from the wilderness in the south to Lebanon in the north. It will extend all the way to the great River Euphrates in the east (including all of Syria) and all the way to the Mediterranean Sea in the west.