John 3:6

The necessity of the new birth is further exhibited by a comparison of the first and second birth: τὸ γεγεννημένον ἐκ τὴς σαρκὸς σάρξ ἐστι · καὶ τὸ γεγεννημένον ἐκ τοῦ Πνεύματος, πνεῦμά ἐστι. The neuter is used because the speaker “wishes to make His statement altogether general” (Winer, 27, 5), whatever is born. The law is laid down in Aristotle (Eth. Maj., i., 10), “Every nature generates its own substance,” flesh, flesh; spirit, spirit.