The Virginity of Mary in Scripture
Christians accept from Holy Scripture the belief that Mary of Nazareth,
mother of the Lord, was a virgin.
Matthew 1:22-23
All this took place to fulfill what the Lord had said through the
prophet: "Behold, the virgin shall be with child and bear a son,
and they shall name him Emmanuel," which means "God is with
us."
Isaiah 7:14
The virgin shall be with child, and bear a son, and shall name him
  Immanuel.