anyārthaṃ prerito vāyur yathā nānyaṃ karoti saḥ / tathānyavarṇasaṃskāraśakto nānyaṃ kariṣyati //
"Just as an air-current set forth for [the purpose of] one [sound] does not produce another [sound], similarly [that which is] capable of [producing] the refinement for one phoneme will not produce another."