{ She said: My Lord, how will I have a child, as no man has touched me? He said: That is how Allah creates what He wishes whenever He decrees a matter; indeed He says to it “Be” and it is } Al ‘Imran 47

It was narrated that Jibril (peace be upon him), when he said to her { That is how Allah creates what he wishes } , he said: This is what your Lord has said, He who is Most High and acts with ease. He blew into the opening of her robe and her sleeve; Ibn Juraij said this. Ibn ‘Abbas said: Jibril took hold of the sleeve of her shirt with his finger and blew into it, and she immediately became pregnant with ‘Isa [Jesus]. And others besides these have spoken concerning what comes as evidence in her surah, Allah Most High willing. Some have said that the breath of Jibril came down into her womb, and from this she conceived. Some have said that it is not proper that this creation should be attributed to Jibril’s breath, since the child would then become offspring of angels and of men. The reason for this is that Allah Most High, when he created Adam and took hold of the covenant of his progeny, He made some fluid in the backbones of the fathers and some in the wombs of the mothers; and whenever the two fluids come together, it becomes a child. But Allah Most High made both fluids in Maryam, some in her womb and some in her backbone. Jibril blew into it in order to arouse her desire, since a woman does not become pregnant if her desire is not aroused. And when her desire was stirred up from Jibril’s breath, the fluid that was in her backbone dropped down into her womb, and two fluids mixed together, and she conceived from this. This is the word of the Most High { Whenever He decrees a matter } meaning whenever He wants to create a creation, indeed He says to it: "Be."