法華義疏 8.25

8.25

窮子通迷悟，今言信解故用別以立名；卉木通於毒藥，今云藥草亦從別為稱。

The impoverished son applies generally to delusion and awakening; here, it speaks of 'Belief and Understanding,' so it establishes its title from the specific. Plants apply generally to poisonous plants as well; now it says 'medicinal herbs,' also taking its designation from the specific.