What does Isaiah 7:14 mean?
This verse is familiar to believers around the world, mostly because it is quoted in Matthew 1:23. Isaiah foretells that the promised Messiah, Jesus, will be born of Mary, who will conceive without the involvement of any human father. Critics point to the Hebrew words used to deny the reference to a virgin birth. However, evidence from both language and history support that this was the intended meaning.Ahaz has refused God's command to define a miraculous sign (Isaiah 7:12). This would have been clear evidence that God's solution to the invading armies would happen as promised. Likely, this was because Ahaz didn't want to follow God's plan—and certainly didn't want to be faced with proof of it. Now the Lord insists on giving supernatural evidence, anyway. This will be a sign for Ahaz, yes, but it will also pass beyond the house of David to impact all the nations of the world.
In the New Testament, Mary's fiancée, Joseph, learned his future wife was already pregnant. An angel tells him, "Joseph, son of David, do not fear to take Mary as your wife, for that which is conceived in her is from the Holy Spirit. She will bear a son, and you shall call his name Jesus, for he will save his people from their sins" (Matthew 1:20–21). Then Matthew noted (Matthew 1:22) that this was happening to fulfill Isaiah's words: a reference to this verse (Matthew 1:23).
The sign is that a virgin will conceive and become pregnant. Scholars have argued about the translation of this verse for centuries. The word typically translated "virgin" is 'alma in Hebrew. This most literally means a "young maiden." In the strictest sense, it does not require virginity. It could be used of any woman of marriageable age who was not married. And yet, in that era, it would have been highly unusual for an unmarried woman not to be a virgin. Linguists point out that Isaiah could have used the Hebrew word betula, which explicitly means "virgin," if he intended to be clear this woman will never have had sex. He could have used the word ʾišŝa if he wanted to just say "woman." And yet, the implication of virginity seems clear to the Jewish perspective. Hebrew scholars translated the Old Testament into Greek several centuries before the birth of Jesus. This translation, the Septuagint, used the Greek term parthenos, which explicitly means "virgin."
For those who believe both Matthew and Isaiah to be the revelation of God, there is no question about what the term means, at least in Matthew's context. The messenger angel is clear that the "young woman" Mary became pregnant by the Holy Spirit and not by any man. She was a virgin who conceived and gave birth to Immanuel, a Hebrew phrase meaning "God with us." Isaiah tells Ahaz that the sign from the Lord is that a virgin will have a baby and that baby will somehow represent God being with us.
The remaining question is whether this baby will be born in Isaiah's day or if it only points to the far-off birth of Jesus. Many scholars understand both to be true. They describe this as a sign with a "double fulfillment." In addition to Jesus' birth fulfilling Isaiah's prophecy, another baby will soon be born, as well, to show that God is with His people. This might well be why Isaiah was inspired to use a term like 'alma here. In the immediate context, a young woman could conceive normally, and the birth would be a point of reference for how quickly things would happen (Isaiah 7:16). Before that child is more than about three years old (Isaiah 7:16), the threat to Jerusalem from Syria and Israel will have vanished. In the prophetic context, clearly implied, there would be a birth which was miraculous in-and-of-itself, pointing to the Messiah.