Yochanan 3:3-8

In reply, he said to him, Omein, omein, I say to you, unless someone is born anew, he is not able to see the Malchut HASHEM. Rav Nakdimon says to Rebbe, Melech HaMoshiach, How is a man, being old, able to be born? Surely he is not able into the womb of immo a second time to enter and to be born? In reply, Rebbe, Melech HaMoshiach said, Omein, omein, I say to you: unless someone is born of mayim and Ruach Hakodesh, he is not able to enter into the Malchut HASHEM. That which is born of basar is basar, and that which is born of the Ruach is ruach. Do not marvel that I said to you, It is necessary for you to be born again, born anew. The ruach (wind, Spirit) blows where it wishes, and the sound of it you hear, but you do not have da'as of where it comes from and where it goes; so it is with everyone having been born of the Ruach Hakodesh.