Matthew 1:20-23
1:20 When he had contemplated this, an angel of the Lord appeared to him in a dream and said, “Joseph, son of David, do not be afraid to take Mary as your wife, because the child conceived in her is from the Holy Spirit.
1:21 She will give birth to a son and you will name him Jesus, because he will save his people from their sins.”
1:22 This all happened so that what was spoken by the Lord through the prophet would be fulfilled:
1:23 “Look! The virgin will conceive and bear a son, and they will call him Emmanuel,” which means “God with us.”