His meaning: "Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he can not 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." Our Lord's reference to water would not have been unintelligible to Nicodemus; every one in Judæa knew that the Baptist had insisted on immersion in water as a symbol of the purification of the soul of man. Certainly, in connecting "water" with the Spirit and the new birth, our Lord's language, glancing at that of the prophet, went very far beyond this. He could only be fully understood at a later time, when the sacrament of baptism had been instituted, just as the true sense of His early allusions to His death could not have been apprehended until after the crucifixion. But Nicodemus, it is plain, had not yet advanced beyond his original difficulty; he could not conceive how any second birth was possible, without altogether violating the course of nature. And our Lord penetrates His thoughts and answers them. He answers them by pointing to that invisible agent who could achieve, in the sphere of spiritual and mental life, what the Jewish doctor deemed so impossible a feat as a second birth. Nature, indeed, contained no force that could compass such a result; but nature in this, as in other matters, was a shadow of something beyond itself. It was late at night when our Lord had this interview with the Jewish teacher. At the pauses in conversation, we may conjecture, they heard the wind without as it moaned along the narrow streets of Jerusalem; and our Lord, as was His wont, took His creature into His service--the service of spiritual truth. The wind was a figure of the Spirit. Our Lord would not have used the same word for both. The wind might teach Nicodemus something of the action of Him who is the real Author of the new birth of man. And it would do this in two ways more especially.