वा शरि

Operational rule vidhi

When a विसर्ग is followed by a letter from the शर्प्रत्याहार, the विसर्ग optionally remains as विसर्ग.

Word by word (padaccheda)

Indeclinable वा avyayaRight context saptamī · ekavacana

Indeclinable An avyaya such as च "and", वा "optionally", न "not".
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").

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

वा

Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.

Commentary

The विसर्ग is optionally the substitute of विसर्ग when followed by a sibilant (शर्).
As वृक्षः शेते or वृक्षश्शेते, प्लक्षः शेते or प्लक्षश्शेते, वृक्षः षण्डे or वृक्षषण्डे, वृक्षः साये or वृक्षस्साये ॥ Cf. 8.4.40, 8.4.41, for श् and ष् ॥

Vart:- When the sibilant is followed by a hard consonant, there is optionally the elision of the preceding visarga. As वृक्षा स्थातारः or वृक्षाः स्थातारः or वृक्षास्स्थातारः ॥

Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.