8.4.12
एकाजुत्तरपदे णः
Operational rule vidhi
For a समस्तपद, a रेफ or a षकार present in the पूर्वपद causes the णत्व of the नकार present in the एकाच् उत्तरपद whenever the नकार is (1) at end of a प्रातिपदिक, or (2) created due to a नुमागम, or (3) part of a विभक्ति.
Word by word (padaccheda)
Right context एकाच्- उत्तरपदे saptamī · ekavacanaSubstitute / term णः prathamā · ekavacana
- 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.
Full reading
एकाच्-
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
In a compound, the second member of which is a monosyllable, there is ण in the room of न of the second member, provided that the न is at the end of a प्रातिपदिक , or is the augment नुम् , or occurs in a विभक्ति; and when the first member contains a cause of change.
Thus वृत्रहणौ and वृत्रहणः 'the Vritra-killer'. क्षीरपाणि 'Drinkers of milk' : सुरापाणि 'drinkers of wine' : being examples of नुम् 7.3.88, क्षीरापेण and सुरापेण are examples of case-terminations.
Why the letter ण is repeated in this sutra, while its anuvritti was understood from the context? It is repeated in order to show that this is not an optional rule, but an obligatory rule. In fact, it shows that the anuvritti of वा 'optional' ceases, and does not extend further.
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.