Open Matthew 1:18-25.
Matthew 1:22–23 (NIV)
22 All this took place to fulfill what the Lord had said through the prophet: 23 “The virgin will conceive and give birth to a son, and they will call him Immanuel” (which means “God with us”).
Some of the kings of Judah saw themselves as representatives of YHWH, the true king. Ahaz wasn’t one of them. He reigned with little thought of YHWH. At one point he even closed the Jerusalem temple.
Trouble came to Ahaz: the threat of war. Two kingdoms—Israel (the northern tribes) allied with Aram (Syria) to attack Judah. Ahaz was outnumbered and out of options.
If Ahaz stopped seeing himself as the top of the power pyramid and recognized the king above him (YHWH), it would completely change the balance of power. It would be YHWH’s problem to save his people instead of Ahaz’s. Ahaz refused. Isaiah offered him a blank cheque: “Ask YHWH for any sign you want!” But Ahaz didn’t want to see YHWH as the sovereign over him.
Frustrated with this self-obsessed ruler, Isaiah gave him a sign of YHWH’s sovereignty anyway:
Isaiah 7:14, 16 (NIV)
Therefore the Lord himself will give you a sign: The virgin will conceive and give birth to a son, and will call him Immanuel. … Before the boy knows enough to reject the wrong and choose the right, the land of the two kings you dread will be laid waste.
What a sign! A little child would be born in the palace, and before this child was old enough to take responsibility for following God’s commandments, Israel and Syria would threaten Judah no more. That’s exactly what happened. Within the next twelve years, Israel and Syria fell to Assyria. Even before then, this child represented the Immanuel truth, the reality that God was present, sovereign over Judah, even if Ahaz didn’t know it.
There’s something beguiling about a child. We lower our defences. We drop our guard. That’s exactly what Ahaz was intended to do each time he saw the child who symbolized the presence of God, their heavenly ruler.
Unlike some modern readers, Matthew knew the story of the Immanuel child who symbolized the divine ruler’s presence over the courts of Ahaz, the king who recognized no power higher than himself. Matthew has given the account of Jesus’ origins, his “genesis” (1:1). After tracing his lineage through Israel’s story to “Joseph the husband of Mary” (1:16), Matthew tells us that actually there’s more going on. There’s no direct paternal link between Joseph and Jesus. Jesus birth was a creative miracle of the Holy Spirit within Mary’s womb (1:18). We’re talking a virginal conception (1:20). There is therefore a sense in which this child is God’s Son.
Now kings of Israel and Judah could be described as sons of God in the sense that they were earthly princes who represented the true heavenly king (e.g. Psalm 2:7; 2 Samuel 7:14). That’s exactly what Ahaz failed to recognize. The child who lived in Ahaz’s palace merely represented the Immanuel truth. But now, Matthew says, the Immanuel truth is embodied in a new way. Jesus is God’s Son quite literally—born without a human father. He is the Immanuel reality: God present with us, as our sovereign, the one to whom we must submit.
So it’s not that Isaiah predicted a virgin birth: he didn’t. It’s that God has done now in Jesus what he had always intended (i.e. his divine presence among us, God with us) but in a new and staggeringly different way.
Matthew’s claim would have been quite a challenge for some of this audience. The danger is that they, like Ahaz, would fail to recognize their true king living among them.
What others are saying
R. T. France, The Gospel of Matthew, NICNT (Grand Rapids, MI: Eerdmans, 2007), 56–57:
Isaiah’s choice of this unusual word in connection with childbirth therefore draws attention; it does not explicitly mean “virgin” (the Hebrew for which is betûlâ), but it suggests something other than a normal childbirth within marriage. It was presumably on this basis that LXX translated it by parthenos (“virgin”). Matthew is following the LXX, but the Hebrew underlying it is sufficiently unusual to suggest that it was not an arbitrary translation.
The second problem is that Isaiah’s prophecy, uttered to Ahaz in about the year 735 b.c., is not about an event in the distant future. Its point is to specify the time of the imminent devastation of both Judah’s enemies and Judah herself through the Assyrian invasion: it will be before the son called Immanuel, soon to be born, has grown up (Isa 7:15–17). This raises an issue which we will note several times in Matthew’s use of OT prophecy, that whereas we prefer to think of a single specific fulfillment of a prophet’s prediction, Matthew’s typological interest leads him rather to find patterns which will recur repeatedly throughout God’s dealings with his people.
Ulrich Luz, Matthew 1–7: A Commentary on Matthew 1–7, Hermeneia (Minneapolis, MN: Fortress Press, 2007), 96:
Allusions to “God-with-us” run through the entire Gospel (e.g., 17:17; 18:20; 26:29). Above all, with the last verse of his Gospel (“I am with you always until the end of the world,” 28:20) Matthew has created an inclusion that marks out a basic theme: the presence of the exalted Lord with his church establishes him as Immanuel, as God with us. Thus the Jewish Christian Matthew has put his story of Jesus in an extremely high christological perspective. Although he did not identify Jesus with God, he probably implied that for him Jesus is the form in which God will be present with his people and later with all nations.
Michael Bird, “N. T. Wright: The Church Continues the Revolution Jesus Started” in Christianity Today, October 2016:
In particular, the victory which Jesus believed he would win in this way was, in Israel’s Scriptures, the victory of God himself. That is a whole other theme, but an important one for us, in case we should imagine that this human vocation was all about twisting God’s arm to do something he might not otherwise have done. Jesus believed that, in being obedient to this human vocation, he was embodying or, if you like, incarnating the loving, rescuing God of whom Israel’s Scriptures had been speaking all along. Jesus’ own sense of vocation and (what we loosely call) “identity” lies at the heart of the church’s developed belief.