Direct biblical statement
Matthew 1:22–23
Emmanuel
22 Now all this was done that it might be fulfilled which the Lord spoke by the prophet, saying:
23 Behold a virgin shall be with child, and bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us.
Douay–Rheims · Challoner revision · Matthew 1:22–23
Why this matters
Matthew explicitly interprets Jesus’ birth from the virgin through Isaiah’s Emmanuel prophecy. This is an expressed scriptural fulfillment in Matthew, though Isaiah’s original historical setting also deserves attention.