7.3.51
इसुसुक्तान्तात् कः
Operational rule vidhi
A ठकार present at the beginning of a प्रत्यय is converted to 'क्' for an इस्-प्रत्ययान्त अङ्ग, उस्-प्रत्ययान्त अङ्ग, उक्-वर्णान्त अङ्ग and तकारान्त अङ्ग.
Word by word (padaccheda)
Left context इस्- उस्- - त- अन्तात् pañcamī · ekavacanaSubstitute / term कः prathamā · ekavacana
- Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
- Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
Dotted words are technical terms, dashed ones pratyāhāras (names for classes of sounds or affixes). Hover or tap one to see its card.
Full reading
इस्-
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
क is substituted for ठ after a अङ्ग (stem) ending in 1. इस् 2. उस् 3. उ or ऊ 4. ॠ and 5. त्।
As सार्पिष्कः, धानुष्कः, याजुष्कः, नैषादकर्षुकः, शाम्बरजम्बुकः, मातृकम्, पैतृकम्, औदश्वित्कः, शाकृत्कः, याकृत्कः ॥ The इस् and उस् are the affixes of that name, therefore not here, आशिषिकः (= आशिषा चरति), औषिका (= उषा चरति) ॥
Vart:- So also after दोष, as दौष्कः (दोर्भ्यां चरति) ॥
The word सार्पिष्कः is formed by ठक् of तदस्य पण्यं, 4.4.51 and स is changed to ष by इणः षः 8.3.39. भानुष्कः is by ठक् of प्रहरणं ॥ याजुष्क is by ठक् of दीव्यति ॥ नैषादकर्षुकः &c by ठञ् of भवादावर्थे ओर्देशे ठञ् ॥ मातृकः by ठञ् of तत आगतः, ऋतष्ठञ् ॥ औदाश्वत्कः by ठक् 4.2.19 शाकृत्कः by ठञ् of संसृष्टे 4.4.12.
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.