We are familiar with the New Testament use of the virgin-born son passage as a reference to Jesus in Matthew 1:23, but most of us have never considered how Matthew came to this conclusion. Matthew does not use all his Old Testament prophecies the same way. Some of Matthew’s other Scripture texts refer in the Old Testament not to Jesus but to Israel; for instance, “out of Egypt I called My son” clearly refers to Israel’s exodus from Egypt in Hosea 11:1, but Matthew applies it to Jesus’ exodus from Egypt (Matt. 2:15). Matthew is not saying that Hosea had Jesus in mind; he is saying that Jesus as the ultimate son of Abraham (Matt. 1:1) recapitulates Israel’s experiences (for instance, his forty days in the wilderness and His quotations from Deuteronomy in Matt. 4:1-11). That very chapter of Hosea goes on to speak of a new exodus, a new era of salvation comparable to the old one. Matthew quotes Hosea 11:1 because he knows that Hosea himself pointed to a future salvation.
So before we read Matthew’s application of Isaiah 7:14 into Isaiah, we must carefully examine what Isaiah 7:14 means in context. (If this exercise makes you nervous, you can skip to our conclusion, but make sure you come back and follow our discussion the whole way through.) Although Matthew 1:23 clearly refers to Jesus being born of a virgin (the Greek term is clear), scholars dispute whether the Hebrew words in Isaiah also refer necessarily to a “virgin” or, more generally, to a “young woman.” For the sake of argument, we will avoid this point and examine the context only.
The king of Assyria was encroaching on the boundaries of Israel (the kingdom of Samaria) and Syria (Aram, the kingdom of Damascus). Realizing that they were in trouble, they tried to get the king of Judah (the kingdom of Jerusalem) to join them in fighting the Assyrians. When he proved uncooperative, they sought to force him to join their coalition. At this time, God sent the prophet Isaiah to Ahaz, king of Judah, to warn him not to join the coalition of Israel and Syria. (Keep in mind that Judah and Israel were two separate countries by this point in their history.) Syria or Aram (represented by its capital Damascus) and Israel or Ephraim (represented by Samaria) would be crushed shortly (7:4-9).
Isaiah even offered the Judean king Ahaz a sign to confirm that Aram and Israel would quickly fall (7:10-13). The sign was one that would get Ahaz’s attention: a woman would bear a son and name him Immanuel, “God is with us” (7:14). Before the son would know right from wrong, while still eating curds (7:15; this was in Isaiah’s day, 7:21-25), the Assyrian king would devastate Aram and Israel (7:16-20). In other words, the child would be born in Ahaz’s generation! But then, why was the son named, “God is with us”? Perhaps for the same reason that all Isaiah’s children bore symbolic names (8:18), just as Hosea’s children were prophetic signs to the northern kingdom of Israel in roughly the same period (Hosea 2:4-9). We will come back to this point later in our discussion.
After offering this prophecy to Ahaz, Isaiah was sent in to “the prophetess” (presumably his young, new wife, who may have also had the gift of prophecy) and she got pregnant. They named the son “Mahershalalhashbaz”—”Swift is the booty, speedy is the prey.” God said to name the child this as a sign to Judah that God would quickly give Judah’s enemies into the hands of the Assyrian army. Before the boy was old enough to utter the most childish form of, “Mother” or “Father,” Assyria would plunder Aram and Israel (8:1-10). In other words, Isaiah’s own son would be the sign to Ahaz: his birth would be quickly followed by the devastation of the lands to the north that had sought to force Judah into their coalition. Judah needed to know that “God is with us,” and that Aram’s and Israel’s “booty” would be carried away “speedily,” and its “prey…swiftly” (7:14; 8:3).
So why did Matthew think Isaiah 7:14 could be applied to Jesus? Probably not for the same reason we often do. We apply Isaiah 7:14 to Jesus because we never read its immediate context; Matthew probably applied it to Jesus because he read past the immediate context to the broader context of surrounding passages. As we mentioned before, Isaiah’s children were for “signs,” each teaching Judah of what God would do (8:18). The immediate sign of God being with Judah would be the conquest of their enemies to the north; but the ultimate act of God being with them would be when God Himself actually came to be with them. In the very next passage, Isaiah announces a hope that would extend beyond Judah even to the northern kingdom of Israel (9:1-2), a conquering king, a child who would be born to the house of Judah (9:3-7). Not only would He be called “God is with us”; like his other titles, which appropriately apply to Him, “Mighty God” would apply to Him (9:6, a title of God also found in the context, 10:21). This Davidic King (9:7) would be God in the flesh (9:6); in the ancient near East, where Israel may have been unusual for not turning its kings into gods, Isaiah certainly would not have risked calling this king “Mighty God” if he had not meant that God Himself was coming to reign as one of David’s descendants. Matthew was right, but not for the reason we would have assumed!
Some critics of Matthew, who believe that he simply did not know the context, are skeptical. It is fair to point out to them that Matthew demonstrates his knowledge of the context just three chapters later. There he applies to Jesus a passage from Isaiah 9:1-2 (Matt 4:15-16), showing that the context of Isaiah 7:14 remains fresh in his mind!