Name known only to Himself
In Revelation 19:12, this symbolically means that what the Word is like in its spiritual and celestial senses, no one sees but the Lord, and the person to whom He reveals it. (Apocalypse Revealed 824)
Matthew 1:18
18
Now the birth of Jesus Christ was like this; for after his mother, Mary, was engaged to Joseph, before they came together, she was found pregnant by the Holy Spirit.