अतो हलादेर्लघोः

Before the इट् beginning s-Aorist of the परस्मैपद the short अ of the root gets optionally वृद्धि when the अङ्ग (stem) begins with a consonant and the अ is prosodially short by being followed by a simple consonant.
Thus अकणीत् or अकाणीत्, अरणीत् or अराणीत् ॥ Why do we say 'of अ' ? Observe अदेवीत्, असेवीत् ॥ Besides this patent objection, there is another, not so manifest. If we had not taken अतः, the sutra would have ordained Vriddhi of every vowel (अचः 7.2.3), the Vriddhi so ordained would be an अच् pertaining Vriddhi, and not an इक्-pertaining Vriddhi. Therefore ङित् affixes will not debar such Vriddhi, for the क्ङिति च 1.1.5, debars only इग्लक्षणा Vriddhi. Therefore कुटादि roots after which सिच् is ङित् 1.2.1, will get Vriddhi, which is not desired. Therefore we have only one form of न्यकुटीत्, न्यपुटीत् ॥

Why do we say 'beginning with a consonant'? Observe मा भवानशीत्, मा भवानटीत् from अश् and अट् ॥ Why do we say 'prosodially short'? Observe अतक्षीत्, अरक्षीत् ॥

But why does not vriddhi take place in अचकासीत् from the root चकास् (Ad. 65) ? The vriddhi does not take place on the maxim येन ना व्यवधानं तेन व्यवहितेऽपि वचनप्रामाण्यात्; for the rule applies to short अ only when a consonant intervenes between it and the affix, and not when both consonants and vowels intervene. In चकास् not only the consonants क् and स् intervene but also the vowel आ ॥ Hence there is no vriddhi. Moreover, the व्यवधान can be by one letter and not by more than one letter. Therefore, applying this maxim, the word लंघाः might have been omitted from the sutra without any detriment. In that case, the form अतक्षीत् from the root तक्ष (Bhu 685) will be explained by saying that rule 7.2.7 does not apply to it, because two consonants intervene between अ and the affix. In this view of the case, the employment of the word लघोः in the sutra is for the sake of distinctness only.

The word इट् is understood in this sutra, so that the rule applies to सेट् aorist. The rule therefore, does not apply to Anit aorist, as अपाक्षीत् ॥

The form अपिपठिषीत् the aorist of the Desiderative root, is explained by saying that the long आ of vriddhi is elided by 6.4.64.