Luke 1:33-35

33 And he shall reign over the house of Jacob; for ever, and of his kingdom there shall be no end.

34 Then said Mary to the angel, How shall this be, seeing I know not a man?

35 And the angel answering said to her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee; therefore also that Holy thing which shall be born, shall be called the Son of God.