tathā hi mātraśabdena sarvaviśeṣatyāge kṛte kimaparamanyat sāmānyācchabdamātraṃ bhavet / tasmāt sāmarthyād bhavadbhiḥ śabdatvam evānityaṃ pratijñātaṃ syāt /
For when all particular features are excluded by the word "mere", what else could "mere śabda" be other than the universal? Therefore, by implication, your proposition would amount to declaring that śabdatva itself is non-eternal.