“A person can receive nothing unless it is given to him from heaven.” (John 3:27)
John repeats a point that Christ actually makes in the discussion with Nicodemus recorded in the same chapter (John 3). The story is well known. Jesus has been doing (and saying) some pretty impressive things. He comes to Jesus by night, because he was a Pharisee of the Sanhedrin after all, and wonders how it is possible that Jesus is doing this work.
It is the similar question that John’s disciples asked him: how is it possible that Jesus is allowed to do this work?