Amulek’s literary contrast hinges on the concept of law. While they accuse him of speaking against their law, Amulek claims that he has actually spoken with their law but against them. What exactly has Amulek said “with” their law?
Amulek spoke “against” their lawyers who, as those charged with preserving the law, should have been its quintessential representatives. But he spoke “with” the law (and against them) by quoting Mosiah2’s declaration. A modern audience would not automatically assume that Mosiah2’s declaration constituted a “law,” but an ancient audience would understand it differently. Amulek set Ammonihah’s law (as articulated by the lawyers) against Mosiah2’s law (which governed all cities in Zarahemla’s polity) and obviously gave priority to Mosiah2’s law.