हरतेर्दृतिनाथयोः पशौ

Operational rule vidhi

When the agent indicated is an animal, the affix इन् comes after the verb हृ 'to take', the object in composition with it being the words ददृति 'a leather bag' and नाथ 'a master'.

Word by word (padaccheda)

Left context हरतेः pañcamī · ekavacanaRight context दृति- नाथयोः saptamī · dvivacanaRight context पशौ 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").

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

हरतेः दृति-नाथयोः पशौ

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

Commentary

When the agent indicated is an animal, the affix इन् comes after the verb हृ 'to take', the object in composition with it being the words ददृति 'a leather bag' and नाथ 'a master'.
Thus दूतिहरिः 'a dog' (a carrier of skin); नाथहरिः 'a beast' (that carries its master).

When the words formed do not denote an animal, the affix अण् is employed; as दूतिहारः 'a water-carrier' (a carrier of a leather-bag for holding water). नाथहारः 'a carrier of his master'.

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