Damascus, the capital of present-day Syria, is one of the oldest continuously inhabited cities in the world. Archaeological evidence shows that the city was inhabited as far back as 8000 to 10,000 BCE. However, Damascus was not recorded as an important city until the arrival of the Arameans. Aramaean, Assyrian, and Hebrew texts all mention an Aramaean state (Aram Damascus) with its capital in Damascus in the 9th century BCE. This state reached its peak under the king Hazael, who defeated the kings of Israel and Judah during his reign.
Around 735 BCE, Ahaz (also called Jehoahaz) reigned as king of Judah. Rezin, king of Aram, and Pekah, king of Israel, went to war with Judah. The reasons for this conflict are not clear. An historical explanation is that Ahaz had already been loyal to or a vassal of the Assyrian king, Tiglath-Pileser III. With Rezin and Pekah organizing a rebellion against Assyria, Judah was an excellent target for them[1]. An alternative explanation is that Rezin and Pekah were pressuring Ahaz to join the coalition against Assyria. One biblical explanation is that God sent Rezin and Pekah to attack Judah[2][3]. Another biblical explanation is that Rezin and Pekah had engaged in an evil war against Judah, in order to put a different king on the throne of Judah[4].
According to the Bible, Isaiah at this point was sent to Ahaz by God. Isaiah's purpose was to tell Ahaz that Rezin and Pekah would not succeed in overthrowing him[5]. Isaiah supplied the following prophecy: that a young woman would, in the very near future, give birth to a son whom she would name Immanuel, and that before this son was old enough to know the difference between good and evil, that both Rezin and Pekah would be dethroned or dead.[6]
Isaiah's prophecy can be broken down into two parts — the imminent sign, and the end result. Both parts were prophesied. The point of the imminent sign was to give Ahaz the faith to carry on to see the end result. The imminent sign was the birth of a boy who would be named Immanuel. The end result was that both Rezin and Pekah would be dethroned or dead. By setting the timeframe of the end result based on the timeframe of the sign, Ahaz would know, after seeing the fulfillment of the sign, that the fulfillment of the end result was imminent.
Regardless of the reasons for the conflict, Assyrian and biblical records agree on the course of action upon which Ahaz decided. An inscription preserved in clay records that Tiglath-Pileser III (also called Pul) received tribute from Ahaz[7], which corroborates the biblical account of Ahaz paying tribute to Tiglath-Pileser III in order to secure Assyria's help against Aram and Israel[8][9]. So Ahaz sought the support of Assyria against his foes, rather than trusting God.
Thus, examining the full context of Isaiah 7:14, the fulfillment of the prophecy of Immanuel was clearly intended for the time of Ahaz, in the 8th century BCE, when Judah was threatened by the kings of Israel and Aram. It was not a prophecy whose fulfillment was intended for seven centuries after the death of Ahaz. Considering that Rezin and Pekah were no more than mortal men with standard, 70-year lifespans, a prophecy that said, "Seven hundred years from now, your foes, Rezin and Pekah, will no longer rule Aram and Israel," would hardly be a valuable prophecy. Nor would it be any consolation to Ahaz.
However, the author of Matthew somehow finds it appropriate to attribute the prophecy of Isaiah to the birth of Jesus[10]. First, he misquotes Isaiah, stating that a virgin would give birth to a son. Isaiah only said that a young woman would give birth to a son. Second, Jesus was never called Immanuel. Third, the birth of Jesus would have been roughly 700 years after Ahaz, Rezin, and Pekah were all dead. So whether or not there was a Jesus, and whether or not this Jesus was born of a virgin, attempting to apply the prophecy of Isaiah 7:14 to this person is complete folly. The birth of a boy named Immanuel was a sign intended for Ahaz, and Ahaz had already been dead for 700 years.
References
1. John, Paul (2004). The Genesis of Misconception. Trafford Publishing. pp.64. ISBN 1412034817, 9781412034814.
2. 2 Kings 15:37.
3. 2 Chronicles 28:5.
4. Isaiah 7:1,5-6.
5. Isaiah 7:7.
6. Isaiah 7:14-16.
7. Pritchard, James Bennett (1973). The Ancient Near East, Volume 1: An Anthology of Texts and Pictures. Princeton University Press. pp 193. ISBN 0691002002.
8. 2 Kings 16:7-9.
9. 2 Chronicles 28:16.
10. Matthew 1:23.