तिसृभ्यो जसः

Thus ति॒॒स्र꣡स्तिष्ठन्ति ॥ This debars the Svarita accent ordained by 8.2.4 The word तिसृ (feminine of त्रि 7.2.99 meaning 'three' is always plural. There are singular or dual cases of this numeral; of the seven plural cases, the accusative plural will have acute on the final by 6.1.174; the remaining cases (Instrumental, Dative, Ablative, Genitive and Locative) have affixes beginning with a consonant, and by 6.1.179 they will be udatta. Thus the only case not covered by any special rule is जस् (nominative plural); which would have been Svarita, but for this rule. If जस् be the only case not provided for, then merely saying तिसृभ्यः would have sufficed to make the rule applicable to जस् only, why has then it been employed in the sutra? This is done, in order that in compounds, where तिसृ may come as a subordinate member, and where singular and dual endings will also be added, this rule will not apply. Had जस् been not used in this sutra, then in the case of simple तिसृ there would be no harm, but when it is second member in a compound there would be anomaly. Thus अतितिस्रौ would have become end-acute. But that is not desired. It is svarita on the final by 8.2.4.,