लिङ्सिचावात्मनेपदेषु

After roots ending in a consonant, that adjoins a vowel of इक् प्रत्यहार , the substitutes of the -- विधिनिमन्त्रणामन्त्रण अधीष्टसम्प्रश्नप्रार्थनेषु लिङ् 3.3.161 and सिच् -- च्लेः सिच् 3.1.44, when they begin with a consonant of झल् प्रत्यहार , are कित् when the आत्मनेपद affixes follow.
The sutra consists of two words लिङ्सिचौ and आत्मनेपदेषु, literally meaning "the affixes lin and sich in the Atmanepada." The other phrases, given in the above text must be supplied from the previous sutras, to complete the sense. The anuvritti of the word सन्, that began with sutra 1.2.8, does not extend further. As:- भित्सीष्ट 'may he break' and भुत्सीष्ट 'may he know,' अभित्त 'he broke', अबुद्ध 'he knew.'

Thus the root भिद् ends with a simple consonant, is preceded by इ a letter of ik pratyahara ; after this root the jhaladi affix सीष्ट of Benedictive in the Atmanepada is treated like कित्; therefore there is no guna substitution of the vowel of the root before this affix. भिद् + सीष्ट = भित्सीष्ट. Similarly in the Aorist we have अभित्त = अ + भिद् + सिच् + त, the स of the Aorist being elided by 8.2.26. So also बुध् + सीष्ट = भुत् + सीष्ट 8.2.37 = भुत्सीष्ट.

If the final consonant is not preceded by an ik vowel, this rule will not apply. Thus Ben. यज् + सीष्ट = यष् + सीष्ट 8.2.36 = यक् + सीष्ट 8.2.41 = यक्षीट 8.3.58. Similarly its Aorist is अयष्ट. Had the affixes सीष्ट and त been kit, they would have caused samprasarana of य by 6.3.16.

This rule will not apply, if the Benedictive and Aorist affixes are Parasmaipadi. Thus the Aorist of सृज् 'to let off,' is अ + सृज् + सीत् = अ + सृज् + अ + ज् + सीत् 6.1.58 = अस्रज् + सीत् 6.1.77 = अस्राक्षीत् (VII.2. I). Similarly from दृश् we have Aorist Parasmaipadi अद्राक्षीत्. Had the Aorist been कित्, rule 6.1.58 (अम् is the augment of the verbs सृज् and दृश् when an affix beginning with a jhal and not having an indicatory क् follows), would not have applied.

This rule will also not apply, if the verb ends in a vowel. Thus of the verb चि, we have Ben. चेषष्टि, Aor. अचेष्ट. Had the affixes been कित्, there would have been no guna substitution of i into e.

The rule will not apply, if these affixes are not jhaladi, but take the augment इट्. Thus Ben. वृत् + इषीष्ट = वर्तिषीष्ट, so also Aorist अवर्तिट. Had they been कित्, there would have been no guna substitution.

This rule, of course, is confined to the Benedictive and the Aorist. Other tenses will not be affected by this rule. Thus the Ist and 2nd Future of द्विष् is द्वेष्टा and द्वेक्ष्यति.