The judgment itself is founded, as in the others already considered, upon thoughts and incidents connected with Old Testament history. The first of these is the river Euphrates. That great river was the boundary of Palestine upon the northeast. "In the same day the Lord made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates;"[221] and in the days of Solomon this part of the covenant appears to have been fulfilled, for we are told that "Solomon reigned over all kingdoms from the river" (that is, the Euphrates) "unto the land of the Philistines, and unto the border of Egypt."[222] The Euphrates, however, was not only the boundary between Israel and the Assyrians. It was also Israel's line of defence against its powerful and ambitious neighbour, who had to cross its broad stream before he could seize any part of the Promised Land. By a natural transition of thought, the Euphrates next became a symbol of the Assyrians themselves, for its waters, when they rose in flood, overflowed Israel's territory and swept all before them. Then the prophets saw in the rush of the swollen river a figure of the scourge of God upon those who would not acknowledge Him: "The Lord spake also unto me again, saying, Forasmuch as this people refuseth the waters of Shiloah that go softly, and rejoice in Rezin and Remaliah's son; now therefore behold, the Lord bringeth up upon them the waters of the river, strong and many, even the king of Assyria, and all his glory: and he shall come up over all his channels, and go over all his banks: and he shall pass through Judah; he shall overflow and go over, he shall reach even to the neck; and the stretching out of his wings shall fill the breadth of Thy land, O Immanuel."[223] When accordingly the Euphrates is here spoken of, it is clear that with the river as such we have nothing to do. It is simply a symbol of judgment; and _the four angels which had been bound at it_, but were now _loosed_, are a token--four being the number of the world--that the judgment referred to, though it affects but a third part of men, reaches men over the whole surface of the globe. When _the hour, and the day, and the month, and the year_--that is, when the moment fixed in the counsels of the Almighty--come, the chains by which destruction has been kept back shall be broken, and the world shall be overwhelmed by the raging stream.