Nuhad Al-Mashnuq in As-Safir reveals (citing Saud Al-Faysal) that Hizbullah was not even invited by the Saudi government, but that Hizbullah invited itself. (I checked the words of Saud Al-Faysal in his press conference in Riyadh: he did say that the visit of the Hizbulalh delegation to Saudi Arabia was requested by Hizbullah.)