DJBA lists s.v. פרזל, but the Mandaic form BZL, the JBA variants ברזל and בזל, as well as a presumed development from bdr, all demonstrate that bzl should be assumed to be the actual root here. Note that the Aruch gives ברזל for the JBA passage.
Page refs. in other dictionaries:
DJBA: 930Jastrow: 154Drower/Macuch: 58a