8.2.9
मादुपधायाश्च मतोर्वोऽयवादिभ्यः
Operational rule vidhi
For the म् of the affix मत् is substituted व if the अङ्ग (stem) ends in म् or अ ( and आ) or if these are in the penultimate position; but not after यव etc.
Word by word (padaccheda)
Left context मात् pañcamī · ekavacanaLeft context उपधायाः pañcamī · ekavacanaIndeclinable च avyayaTarget मतोः ṣaṣṭhī · ekavacanaSubstitute / term वः prathamā · ekavacanaLeft context अयवादिभ्यः pañcamī · bahuvacana
- Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
- Indeclinable An avyaya such as च "and", वा "optionally", न "not".
- 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. Hover or tap one to see its card.
Full reading
मात् उपधायाः च मतोः वः अयवादिभ्यः
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
मतोः → वः / मात् उपधायाः अयवादिभ्यः
Replace matoḥ with vaḥ when it comes after māt upadhāyāḥ ayavādibhyaḥ. Inherited words (anuvṛtti) may add further conditions.
Commentary
For the म् of the affix मत् is substituted व if the अङ्ग (stem) ends in म् or अ ( and आ) or if these are in the penultimate position; but not after यव etc.
After a stem ending in म् or having म् as its penultimate letter, and after a stem ending in अ or आ, or having these letters as its penultimate, there is substituted व् for the म् of मतुप् ॥ First after stems ending in म्, as किंवत् (किंवान्), शंवत् (शंवान्). Secondly म् penultimate : as शमीवान्, दाडिमीवान् ॥ Thirdly a stem ending in अ or आ, as वृक्षवान्, प्लक्षवान्, खट्वावान्, मालावान् ॥ Fourthly अ or आ in the penultimate : as- पयस्वान्, यशस्वान्, भास्वान् ॥
Why do we say "म् or अ ending or म or अ penultimate"? Observe अग्निमान्, वायुमान् ॥ Why do we say "with the exception of यव &c"? Observe यवमान्, दल्मिमान्, उर्म्मिमान् ॥
The following is the list of यवादि words.
1. यव, 2. दल्मि, 3. उर्म्मि, 4. भूमि, 5. कृपि, 6.कुञ्चा, 7. वशा, 8. द्राक्षा, 9. घ्राक्षा ॥ These words either end in म and अ or have these as their penultimate. 10. ध्रजि, 11. ध्वजि, 12. सञ्जि. These are exceptions to 8.2.15. 13. हरित् 14. ककुत्, 15. गरुत् ॥ These are exceptions to 8.2.10. 16. इक्षु, I7. मधु, 18. द्रुम, 19. मण्ड, 20. धुम ॥ These are exceptions to 8.2.11.
This is an akritigana. Wherever in a word, the म् of मतुप् is not changed to व्, though the rules require it, that word should be classified under यवादि class. In the secondary word नार्मतं (= नृमत इदं), the व् change has not taken place, because the अ is here a Bahiranga, the real vowel being ऋ ॥
The word मात् in the sutra is the Ablative of म, i.e. of म् + अ; it is a Samahara Dvandva of these two letters.
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.