Note 6 at Joh 3:10: The new birth was not a reality until Jesus had risen from the dead. This is evident by the fact that Jesus was the first begotten from the dead (Col 1:18, Heb 12:23, and Re 1:5). He was quickened, or made alive, by the Spirit (1Pe 3:18) and became the first born again, or first begotten from the dead.

However, the new birth was prophesied in the Old Testament (Eze 11:19 and 36:25-27), and as a master of Israel, Nicodemus should have understood what Jesus was speaking of.