tulayā sammitam tulyam .
That which is measured by a balance (tulā) is 'tulya' (equal).
āsyam ca prayatnaḥ ca āsyaprayatnam .
āsya and prayatna [together] = āsyaprayatna (a dvandva compound).
tulyāsyam tulyaprayatnam ca savarṇasañjñam bhavati .
That which has equal āsya and equal prayatna receives the designation savarṇa.
kim punaḥ āsyam .
But (punaḥ) what is āsya?
laukikam āsyam oṣṭhāt prabhṛti prāk kākalakāt .
āsya is the ordinary (laukika) [mouth]: from the lips (oṣṭha) on, up to before the larynx (kākala).
katham punaḥ āsyam .
But how (katham) [is the word] āsya [derived]?
asyanti anena varṇān iti āsyam .
'They cast (asyanti) the sounds (varṇa) by means of it (anena)' — thus (iti) āsya.
annam etat āsyandate iti vā āsyam .
Or (vā): 'this food flows into it (ā-syandate)' — thus āsya.
atha kaḥ prayatnaḥ .
Now (atha), what is prayatna?
prayatanam prayatnaḥ .
prayatna is prayatana (exertion, the making of effort).
prapūrvāt yatateḥ bhāvasādhanaḥ naṅpratyayaḥ .
[It is formed] from the root √yat preceded by pra-, [as] a formation denoting the action (bhāvasādhana), with the affix naṄ.
yadi laukikam āsyam kim āsyopādāne prayojanam .
If āsya [means] the ordinary mouth, what is the purpose in the taking-up (upādāna) of āsya [in the sūtra]?
sarveṣām hi tat tulyam bhavati .
For that (the mouth) is the same (tulya) for all [the sounds].
vakṣyati etat : prayatnaviśeṣaṇam āsyopādānam iti .
He will say this: 'the taking-up of āsya is a qualifier (viśeṣaṇa) of prayatna' — thus (iti).