Tertullian

“ We thus understand that what is denied is the Lord’s birth after sexual intercourse (as is suggested by the phrase, “the will of man and of the flesh”) , not His nativity from a woman’s womb. Why, too, is it insisted on with such an accumulation of emphasis that He was not born of blood, nor of the will of the flesh, nor (of the will) of man, if it were not that His flesh was such that no man could have any doubt on the point of its being born from sexual intercourse? Again, although denying His birth from such cohabitation, the passage did not deny that He was born of real flesh ”

“ The expression is in the singular number, as referring to the Lord, “He was born of God.” And very properly, because Christ is the Word of God, and with the Word the Spirit of God, and by the Spirit the Power of God, and whatsoever else appertains to God. ”