3.2.66 हव्येऽनन्तः पादम्

Word by word (padaccheda)

Right context हव्येः saptamī · ekavacanaSubstitute / term अनन्तःपादम् prathamā · ekavacana

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").
Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.

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

हव्येः अनन्तःपादम्

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

Commentary

The affix ञ्युट् comes in the छन्दस् (Vedas) after the verb वह् 'to carry' when it is in composition with the word हव्य 'an oblation to gods', provided that the word so formed does not occur in the middle of a पाद (4th part of a stanza).
As अग्निश्च हव्यवाहनः 'fire, the carrier of oblation to the gods'. (Rig. Ved. I.44.2).

When this word occurs in the middle of a pada, or at the beginning, the form is हव्यवाट्, which is derived by adding the affix ण्वि (sutra (64)). As हव्यवाडग्निरजरः पिता नः 'the never-decaying agni or fire that carries oblation to the gods, is our father'. (Rig. Ved. III.2.2.)

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