tathā vanaṃ tribhuvanaṃ jagat ṣaṇṇagarītyādiṣvasatyapyabhede 'rthasyaikatvasaṅkhyā vyapadiśyata iti
Similarly, in [words] like "vana" (forest), "tribhuvana" (three worlds), "jagat" (world), "ṣaṇṇagarī" (six cities), the singular number is used even though there is no [real] unity in the referent.