सख्यशिश्वीति भाषायाम्

Operational rule vidhi

The forms सखी and अशिश्वी are irregular forms ending in ङीष् found in secular (or vernacular as opposed to Vedic) Sanskrit.

Word by word (padaccheda)

Substitute / term सखी prathamā · ekavacanaSubstitute / term अशिश्वी prathamā · ekavacanaIndeclinable avyayaRight context भाषायाम् saptamī · ekavacana

Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
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. Hover or tap one to see its card.

Full reading

सखी अशिश्वी भाषायाम्

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

Commentary

The forms सखी and अशिश्वी are irregular forms ending in ङीष् found in secular (or vernacular as opposed to Vedic) Sanskrit.
Thus सखीयं मे ब्राह्मणी, and नास्याः शिशरस्तीति = अशिश्वी ॥ Why do we say in vernacular Sanskrit ? Observe सखा सप्तपदी भव and अशिशुमिव मामयं शिशुरभिमन्यते ॥

Sometimes we find these forms in the Vedas also, though rarely, as आधेनवो धुनयन्तामशिश्वी ॥ सखी सप्तपदी भव ॥

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