aśakyaṃ samayasyāsya jāte 'jāte ca kalpanam / nājāte samayo yukto bhāviko 'śvaviṣāṇavat //
Convention cannot be conceived of in relation to either the arisen or the not-yet-arisen. No real convention is possible regarding the not-yet-arisen, just as [no convention is possible] regarding a horse's horn.