8.3.7
नश्छव्यप्रशान्
Operational rule vidhi
In the context of संहिता, when a पदान्त नकार is followed by a letter from छव् प्रत्याहार, which in turn is followed by a letter from अम् प्रत्याहार, then the नकार is converted to रुँ. But this conversion does not happen for the word 'प्रशान्'.
Word by word (padaccheda)
Target नः ṣaṣṭhī · ekavacanaRight context saptamī · ekavacanaSubstitute / term अप्रशान् prathamā · ekavacana
- Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).
- Right context Saptamī (7th case): "when X follows", the operation applies to what precedes (1.1.66 तस्मिन्निति निर्दिष्टे पूर्वस्य). Also a condition or domain ("in the sense of").
- 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
नः अप्रशान्
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
नः → अप्रशान् /
Replace naḥ with apraśān when chavi follows. Inherited words (anuvṛtti) may add further conditions.
Commentary
रु is substituted for the final न् of a word, with the exception of न् of प्रशान् before a छव् letter (छ ठ थ च ट त) which is followed by an अम् letter (vowel, semi-vowel and nasal).
The word अम्परे is to be read into this sutra. The word अप्रशान् in the sutra is in the Nominative case, but it has the force of Genitive.
Thus भवाँश्छादयति or भवांश्छादयति; भवाँश्चिनोति or भवांश्चिनोति; भवाँष्टीकते or भवांष्टीकते, (from the root टीकि 'to go'), भवाँस्तरति or भवांस्तरति ॥
Why do we say 'before a छव् letter'? Observe भवान् करोति ॥ Why do we say 'with the exception of the न् of प्रशान्'? Observe प्रशाम् छादयति, प्रशान् चिनोति ॥ Why do we say 'when अम् follows छव्'? See भवान् त्सरुकः ॥ त्सरु is sword, he who is dexterous in it, is called त्सरुकः (कन् 5.2.64).
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.