The same came to him by night, and said to him, "Rabbi, we know that you are a teacher come from God, for no one can do these signs that you do, unless God is with him."
Rabbi - This was a title of respect conferred on distinguished Jewish teachers, somewhat in the way that the title “Doctor of Divinity” is now conferred. See the notes at John 1:38. Our Saviour forbade his disciples to wear that title (see the notes at Matthew 23:8), though it was proper for Him to do it, as being the great Teacher of mankind. It literally signifies great, and was given by Nicodemus, doubtless, because Jesus gave distinguished proofs that he came as a teacher from God.