तदस्यां प्रहरणमिति क्रीडायाम् णः

Operational rule vidhi

To indicate a sport using an entity used for hitting in that sport, an appropriate तद्धितप्रत्यय gets attached to the प्रथमासमर्थ word indicating the name of the entity used for hitting.

Word by word (padaccheda)

Substitute / term तत् prathamā · ekavacanaRight context अस्याम् saptamī · ekavacanaSubstitute / term प्रहरणम् prathamā · ekavacanaIndeclinable avyayaRight context क्रीडायाम् saptamī · ekavacanaSubstitute / term ः prathamā · ekavacana

Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
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").
Indeclinable An avyaya such as च "and", वा "optionally", न "not".

Dotted words are technical terms. Hover or tap one to see its card.

Pink letters are it-markers (anubandhas), tags dropped by 1.3.9. Hover or tap one for the rule that marks it, or try the it-letter finder.

Full reading

तत् अस्याम् प्रहरणम् क्रीडायाम् णः

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

Commentary

The affix ण to the name of a weapon indicates a game played with that weapon.
The sutra literally translated means: 'that is the weapon in this, denoting play; the affix ण is added' i. e. to a word in the first case in construction, denoting the name of a weapon; ण is added to denote a play. Thus दण्डः प्रहरणमस्यां क्रीडायां = दाण्डा "a game played with sticks". So मौष्टा "a game played with fists".

Why do we say 'a weapon'? Observe माला भूषणमस्यां क्रीडायाम् 'the garland is an ornament in this play'. Here no affix is added to माला ॥ Why do we say 'in denoting a game'? Observe:- खड्गः प्रहरणमस्यां सेनायाम् 'the sword is the weapon in this army'. These words are as a rule in the feminine gender 4.1.4 and 4.1.15, the feminine being formed by आ ॥

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