Isaiah foretells Immanuel.
Fulfilled in the birth of Jesus Christ.
What the Scriptures say
Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel. Isaiah 7:14 · KJV
Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying, Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us. Matthew 1:22-23 · KJV