मृडमृदगुधकुषक्लिशवदवसः क्त्वा

The affix क्त्वा is कित् after मृड् 'to be gracious', मृद् 'to squeeze', गुध् 'to wrap up', कुष् 'to tear', क्लिश् 'to suffer', वद् 'to speak' and वस् 'to dwell'.
After these seven verbs, the gerundial ktva is kit. It might be said, what was the necessity of this sutra? The affix ktva is clearly a kit affix, as it is marked with the diacritical letter क्, and it was useless to call it a kit affix after these verbs. The reason of this apparent repitition is this. Though ktva is a kit affix generally; yet there is a later sutra in this chapter 1.2.18 which declares that the prefix क्त्वा is not कित्, if it is preceded by the intermediate इ. Or in other words, if क्त्वा is added to those verbs, which are called सेट् verbs, viz., that take an intermediate इ, it is not then kit. Thus the verb शी 'to sleep' is सेट्. Therefore शी + इ + त्वा = शे + इ + त्वा = शायित्वा.

Now it happens that all the seven verbs mentioned in the sutra are सेट् verbs, and take an intermediate इ. The क्त्वा before these verbs would have lost its kitness by virtue of sutra 18; therefore arose the necessity of this sutra, to provide in anticipation an exception to that sutra, in favour of these verbs, where the affix ktva is necessarily kit. Thus we have मृडित्वा 'being gracious,' मृदित्वा 'having squeezed,' गुधित्वा 'having wrapped' कुषित्वा 'having torn,' क्लिशित्वा 'having suffered,' उदित्वा 'having spoken,' उषित्वा 'having dwelt.' The व v of वद् and वस् are changed into उ by the rule of Samprasarana 6.1.15.

Moreover in the case of the verbs गुद्, कुष् and क्लिश्, sutra 26 would have made क्त्वा optionally kit; the present sutra makes it necessarily so.