Haymo of Halberstadt
Catena Aurea · Johannesevangelium 3
Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother’s womb, and be born? Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. Marvel not that I said unto thee, Ye must be born again. The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth; so is every one that is born of the Spirit.
(Hom. in Oct. Pent.) Or, Thou canst not tell whence it cometh; i. e. thou knowest not how He brings believers to the faith; or whither it goeth, i. e. how He directs the faithful to their hope. And so is every one that is born of the Spirit; as if He said, The Holy Spirit is an invisible Spirit; and in like manner, every one who is born of the Spirit is born invisibly.