This prophecy was fully realized with the birth of Jesus Christ (Matthew 1:18–24). It is likely that it also partially came true in Isaiah's time, possibly with the birth of the godly King Hezekiah, son of Ahaz, or one of Isaiah's children. The similar verb sequence in Isaiah 7:14 and 8:3 (be with child … give birth … call) and the connection between Immanuel and Maher-shalal-hash-baz in 8:5–10 suggest they were the same person.
The name Immanuel means "God with us." This name symbolized God's presence and protection. God was with Judah:
during the attack by the alliance of Syria and Israel in 734 BC,
during the Assyrian crisis in 701 BC, and
throughout their existence until their fall in 586 BC.
The kingdom of Israel fell during Isaiah’s lifetime, in 722 BC.
Even after that disaster, the promise “I am with you” remained important. God spoke these words to his people during the exile and after they returned home (Isaiah 41:10; 43:2, 5).
The fullest meaning of this promise appears in Jesus Christ, the incarnate Son of God. Incarnate means that God took on human flesh. Jesus is called Immanuel (Matthew 1:23; see also Revelation 12:5).