The term विभक्ति is generally understood to be the process of obtaining पदानि after affixing सुप्-प्रत्यय-s to प्रातिपदिक-s. But in अष्टाध्यायी the term विभक्ति has 2 different contexts and connotations.
- विभक्ति is the process of affixing both – (a) सुप्-प्रत्यय-s to प्रातिपदिक-s and (b) affixing तिङ्-प्रत्यय-s to धातु-s
- सुबन्त-s have some connotation in respect of composing the सूत्र-s, especially regarding अनुवृत्ति.
Maybe, it would be easier to understand this latter connotation by some example. Let us study the following सूत्र-s
1’3’2 उपदेशेऽजननुनासिक इत् = उपदेशे (7-1) अच् (1-1) अनुनासिकः (1-1) इत् (1-1)
- Note उपदेशे (7-1) means the word उपदेश is of 7th case and 1-वचनम्.
- Here, one should also understand the meaning of उपदेश. As has been explained in the article “संज्ञक-s-or-इत्-s-of-पाणिनि” linked here, a धातु, सूत्रम्, गण, उणादि, वाक्य, लिङ्गानुशासनम्, आगम, प्रत्यय and आदेश, all these are उपदेश-s.
- In all these, अनुनासिकः अच् is to be noted to be इत्.
1’3’3 हलन्त्यम् = हल् (1-1) अन्त्यम् (1-1)
- Here there is no word in 7th case. Hence we can bring forward उपदेशे from the previous सूत्रम्. This process of bringing forward is called as अनुवृत्ति.
- In the previous सूत्रम् there are three words having (1-1) as their विभक्ति-वचन analysis. Of these अच् and अनुनासिकः are inter-related. The word इत् is stand-alone. So, that word can also be brought forward.
- With those two अनुवृत्ति-s, this सूत्रम् should be now read as उपदेशे हलन्त्यम् इत्.
- By this the overall meaning becomes, “consonant हल् at the end-position अन्त्यम् of an उपदेश is to be noted to be इत्.”
1’3’4 न विभक्तौ तुस्माः = न (0) विभक्तौ (7-1) तुस्माः (1-3)
- Here, because we have the word विभक्तौ in 7th case, we cannot have अनुवृत्ति of उपदेशे, which also is in the 7th case.
- But we can have अनुवृत्ति-s of both हलन्त्यम् and इत्, both of them being of 1st case. Actually since तुस्माः are specific हल्-s and the सूत्रम् is speaking about these specific हल्-s, we may not have अनुवृत्ति of हल् as a whole. But having अनुवृत्ति of अन्त्यम् would still be logical. Since the अनुवृत्ति should have matching gender, case and number, we should modify them suitably. The सूत्रम् then should be read as न विभक्तौ अन्त्याः तुस्माः इतः, meaning, “तुस्माः, which are as endings of विभक्ति-s, would NOT be considered as इत्-s.”
- This also means that in all other उपदेश-s, which are not विभक्ति-s, हलन्त्यम् stays valid as इत्.
From the above, it is clear that in अष्टाध्यायी the term विभक्ति has 2 different contexts, one as an उपदेश and another, as a consideration of अनुवृत्ति.
There is also a consideration about which विभक्ति is used in what sense, when composing सूत्र-s. For example षष्ठी the sixth case is used when composing सूत्र-s as conceptualized in षष्ठी स्थानेयोगा (1’1’49). The word स्थानेयोगा means substitution, replacement.
In सूत्रम् – इको यणचि (६।१।७७) [इकः यण् अचि]
- इकः (6-1) has षष्ठी of इक्. The इक्-s are “to be substituted” by यण्.
- अचि (7-1) has सप्तमी of अच्. Here सप्तमी is used to connote “when followed by” (अच्).
The purpose of this write-up is to bring forth that विभक्ति-s of words have their general usages in Sanskrit sentences, such as कर्तृपदस्य प्रथमा, कर्मपदस्य द्वितीया, करणकारका तृतीया, सम्प्रदाने चतुर्थी, अपादाने पञ्चमी, अधिकरणे सप्तमी. But in understanding सूत्र-s in अष्टाध्यायी, they have specific connotations, such षष्ठी स्थानेयोगा (“to be substituted by”), सप्तमी “when followed by”. The विभक्ति-s are significant also to understand अनुवृत्ति-s.