Immanuel (Hebrew: עִמָּנוּאֵל meaning, "God with us"; also romanized Emmanuel, Imanu'el) is a Hebrew name which appears in the Book of Isaiah as a sign that God will protect the House of David. The Gospel of Matthew (Matthew 1:22–23) quotes part of this, "a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel", as a prophesy of the birth of the Messiah and the fulfillment of Scripture in the person of Jesus.
The setting is the Syro-Ephraimite War, 734 BCE, which saw the kingdom of Judah pitted against two northern neighbours, the kingdoms of Israel (called Ephraim in the prophecy) and Syria (also known as Aram or Aram-Damascus or Syria-Damascus). Isaiah 7:1–2 tells how the kings of Ephraim and Syria attack Jerusalem when Ahaz refuses to join them in their anti-Assyrian alliance. Ahaz wishes to ask Assyria for help, but Isaiah, at God's command, takes his son Shear-jashub (a symbolic name meaning "a remnant shall return") and assures Ahaz that the two enemy kings will not succeed (Isaiah 7:3–9). Isaiah tells Ahaz of the apparent sign by which he will know that this is a true prophecy: a young woman will give birth to a child whom she will name Immanuel (another symbolic name, meaning "God is with us"), and the lands of the "two kings you dread" will be laid waste before the child is old enough to "reject the wrong and choose the right" (Isaiah 7:13–16).
Isaiah 7:17 follows with a further prophecy that at some unspecified future date God will call up Assyria against Judah: "The Lord will cause to come upon you and your people and your ancestral house such days as have not been seen since Ephraim broke away from Judah—the king of Assyria" (verse 7:17). Verses 18–25 describe the desolation that will result: "In that day a man will save alive a young cow and two sheep…in that day every place where there used to be a thousand vines…will be turned over to thorns and briars" (verses 21–23).Isaiah 8:1–15 continues the previous chapter: the prophet tells of the birth of another child, his own son named Maher-shalal-hash-baz (a third symbolic name), then predicts that after Ephraim and Syria are destroyed the Assyrians will come like a river in flood to "cover the breadth of your land, Immanuel" (Isaiah 8:8).