The Promise with Water

I was reading this evening in Isaiah, and a passage popped out because of two particular geographical mentions. Interestingly Isaiah (27:12) is speaking of a day (in the context of 26 and 27) when “from the river Euphrates to the Brook of Egypt the LORD will thresh out the grain, and you will be gleaned one by one, O people of Israel.” This is the “day of the Lord” spoken of much in the scriptures. What is unique about this passage is that it corresponds to the Abrahamic fulfillment (Gen 15:18), "on that day the LORD made a covenant with Abram, saying, "To your offspring I give this land, from the river of Egypt to the great river, the river Euphrates”.