Luke 1:29-33, 35

She was thoroughly shaken, wondering what was behind a greeting like that. But the angel assured her, “Mary, you have nothing to fear. God has a surprise for you: You will become pregnant and give birth to a son and call his name Jesus. He will be great, be called ‘Son of the Highest.’ The Lord God will give him the throne of his father David; He will rule Jacob’s house forever— no end, ever, to his kingdom.”

The angel answered, The Holy Spirit will come upon you, the power of the Highest hover over you; Therefore, the child you bring to birth will be called Holy, Son of God.