Jim West: Shemaiah was a false prophet who was upbraided by Jeremiah (Jer 29:24-32) for attempting to hinder his work. He is styled "the Nehelamite" (The word means "dweller of Nehelam," but no such place-name is found in the Old Testament. Its etymology, however, suggests a connection with the Hebrew ḥālam, "to dream," and this has given rise to the rendering of the King James Version margin "dreamer."; the Targum reads "who is from Helem" and the name of the false prophet is also found in the Dead Sea Scroll 4Q339 which lists false prophets), and was among those carried into captivity with Jehoiachin. In opposition to Jeremiah, he predicted a speedy ending to the captivity.
Does anyone have any further suggestion concerning the meaning of "Nehelamite"?
Yigal Levin: Radaq (David Qimhi) gives both interpretations: "the dreamer, because he claimed
that God told him in a dream that the exiles would soon be going home, and maybe
a place name".
There actually is a place called Helam, mentioned in the story of David's
battles with the Arameans in 2 Sam. 10:16-17, presumably in northern
transjordan. Whether it is likely to be the origin of a Judahite exile in
Babylon, I don't know.
Michael Avioz: I believe that the text is corrupt. It follows the description of
Jeremiah as ANTOTY, "who comes from Anatoth". The
translation "Shemaiah the dreamer" is incorrect for this is a
passive form. So I guess what we have here is some kind of a joke on
Shemaiah's behalf: he is not a dreamer. He is dreamed of. People
dream of him, he is no real.
Vertaling Bijbel, Kanttekeningen SV, [], Tot Semaja nu, den [40]Nechelamiet, zult gij spreken, zeggende: 40. Dit schijnt een naam te zijn van afkomst of geboorteplaats, maar sommigen menen dat Jeremia, of God zelf hem dezen naam spottenderwijze gegeven heeft, vanwege zijne dromen, want chalam betekent dromen, boven vs.8. Onder vs.31,32, is Nechlamiet.