Matthew 1:18-20

Now the birth of Jesus Christ was on this wise: When his mother Mary had been betrothed to Joseph, before they came together she was found with child of the Holy Spirit. And Joseph her husband, being a righteous man, and not willing to make her a public example, was minded to put her away privily. But when he thought on these things, behold, an angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Spirit.