6.2.169
निष्ठोपमानादन्यतरस्याम्
Operational rule vidhi
In a बहुव्रीहि समास the word मुख denoting 'an actual mouth' has optionally the acute accent (उदात्त) on the final when preceded by a participle in त or by that wherewith something is compared.
Word by word (padaccheda)
Left context निष्ठोपमानात् pañcamī · ekavacanaRight context अन्यतरस्याम् saptamī · ekavacana
- Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
- 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").
Full reading
निष्ठोपमानात् अन्यतरस्याम्
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
In a बहुव्रीहि समास the word मुख denoting 'an actual mouth' has optionally the acute accent (उदात्त) on the final when preceded by a participle in त or by that wherewith something is compared.
Thus प्रक्षालितमुखः꣡ or प्रक्षालित꣡मुखः or प्र꣡क्षालितमुखः ॥ When the final is not acute, then Rule 6.2.110 applies which makes the first member have acute on the final optionally, and when that also does not apply, then by 6.2.1 the first member preserves its original accent, which is that of the gati 6.2.49. Thus there are three forms. So also with a word denoting comparison:- सिंहमुखः꣡ or सिंह꣡मुखः, व्याघ्रमुखः꣡ or व्याघ्र꣡मुखः ॥
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.