6.4.77
अचि श्नुधातुभ्रुवां य्वोरियङुवङौ
Operational rule vidhi
When followed by an अजादि प्रत्यय, the ending इवर्ण and the उवर्ण are converted respectively to इयङ् / उवङ् आदेशs for a) विकरणप्रत्यय श्नु, b) Any धातु, and c) The word भ्रू.
Word by word (padaccheda)
Right context saptamī · ekavacanaTarget श्नु- - भ्रुवाम् ṣaṣṭhī · bahuvacanaTarget य्वोः ṣaṣṭhī · dvivacanaSubstitute / term इयङ्- उवङौ prathamā · dvivacana
- 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").
- Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).
- 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
श्नु-
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
श्नु-
Replace śnu-dhātu-bhruvām yvoḥ with iyaṅ-uvaṅau when aci follows. Inherited words (anuvṛtti) may add further conditions.
Commentary
Before an affix beginning with a vowel there are substituted for उ of नु , the characteristic of the roots of the स्वादिगणः (5th Conjugation) for the final इ , ई , उ and ऊ of a root, as well as for ऊ of भ्रू , the इय् (for इ or ई) and उव् (for उ or ऊ).
Thus आप्नुवन्ति, राध्नुवन्ति, शक्नुवन्ति, from roots of the 5th class. चिक्षियतुः ललुवतुः, लुलुवुः, नियौ, नियः, लुवौ, लुवः and भ्रुवौ and भ्रुवः ॥
Why do we say 'before an affix beginning with a vowel'? Observe आप्नुयात्, शक्नुयात्, राध्नुयात् ॥ Why "of श्नु &c."? Observe लक्ष्यै, लक्ष्याः, वध्वै, वध्वाः ॥ Why "of इ and उ"? Observe चक्रतुः, चक्रुः where the vowel is ऋ ॥
Vart:- The Guna 7.3.84 and Vriddhi 7.2.115 however take place to the supersession of इयङ् and उवङ् as from चि - चयनम् and चायकः, लू - लवनम् and लावकः, with ल्युट् and ण्वुल् ॥
Vart:- In the Chhandas there is deversely the substitution of इयङ् and उवङ् in the case of तन् &c. Thus तन्वं पुषेम or तनुवं पुषेम ॥ विषुवं पुषेम, स्वर्गो लोकः, सुवर्गो लोकः, त्र्यम्बकं यजामहे, त्रियम्बकं यजामहे ॥
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.