John Chrysostom — as excerpted in the Catena Aurea on John 3:4-8

“(Hom. xxv. 1) If any one asks how a man is born of water, I ask in return, how Adam was born from the ground. For as in the beginning though the element of earth was the subject-matter, the man was the work of the fashioner; so now too, though the element of water is the subject-matter, the whole work is done by the Spirit of grace. He then gave Paradise for a place to dwell in; now He hath opened heaven to us. (c. 2.). But what need is there of water, to those who receive the Holy Ghost? It carries out the divine symbols of burial, mortification, resurrection, and life. For by the immersion of our heads in the water, the old man disappears and is buried as it were in a sepulchre, whence he ascends a new man. Thus shouldest thou learn, that the virtue of the Father, and of the Son, and of the Holy Ghost, filleth all things. For which reason also Christ lay three days in the grave before His resurrection. (Hom. xxvi. 1.). That then which the womb is to the offspring, water is to the believer; he is fashioned and formed in the water. But that which is fashioned in the womb needeth time; whereas the water all is done in an instant. For the nature of the body is such as to require time for its completion; but spiritual creations are perfect from the beginning. From the time that our Lord ascended out of the Jordan, water produces no longer reptiles, i. e. living souls; but souls rational and endued with the Spirit.”