When will Israel possess the full territory from the river of Egypt to the Euphrates?
Israel will possess the full territory from the river of Egypt to the Euphrates when the Kingdom is set up. Although David and Solomon partially controlled it, the complete land grant awaits the future Kingdom, when Israel's homeland will extend across the whole Middle East.
Les explains that in Genesis 15, God transferred the title deed of the land to Abraham and made a covenant, promising the land from the river of Egypt to the great river Euphrates. Les notes this area extends through present-day Iraq to the Persian Gulf. Israel has never yet possessed it fully; David and Solomon got part, but not near all of it. Les concludes the day is coming when the land of Israel will actually cover that whole Middle East, which will occur when the Kingdom is set up.
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: