And the angel answered and said unto her, The Holy Spirit shall come upon you, and the power of the Highest shall overshadow you: therefore also that holy thing which shall be born of you shall be called the Son of God.
All Commentaries on Luke 1:35 Go To Luke 1
Justin Martyr
AD 165
But the Virgin Mary received faith and joy, when the angel Gabriel announced the good tidings to her that the Spirit of the Lord would come upon her, and the power of the Highest would overshadow her: wherefore also the Holy Thing begotten of her is the Son of God;