The unique usage in Syriac would seem to be copied from a Babylonian Aramaic source inasmuch as it is in a text descriptive of a Mandaean-like sect; see D. Kruisheer, "Theodore bar Koni’s Ktābā d-’Eskolyon as a Source for the Study of Early
Mandaeism", JEOL 33 (1993-1994),
151-169.