यद्धितुपरं छन्दसि

A finite verb followed by यत् or हि or तु retains its accent in the छन्दस् (Vedas).
The anuvritti of आमन्त्रितं should not be taken in this sutra, but that of तिङ् ॥ Thus with यत्परं we have:- गवां गोत्रमुदसृजो यदङ्गिरः ॥ The verb उदसृजः is the Imperfect (लङ्) 2nd person singular of सृज् of Tudadi class. With हि we have, इन्दवो वा मुशन्ति हि (Rig Ved. I.2.4). The verb उशन्ति is the Present (लट्) Plural of वश् of Adadi class. The samprasarana takes place because it belongs to गृह्यादि class. With न we have, आख्यास्यामि तु ते ॥ By the previous sutra 8.1.30 a verb in connection with यत् would have retained its accent, so also in connection with हि by the sutra 8.1.34, and in connection with तु by 8.1.39: the present sutra is, therefore, a niyama rule. The verb retains its accent when these three Particles only follow and not any other. If any other Particle follows, the verb need not retain its accent. Thus जाये स्वा रोहावैहि ॥ Here रोहाव is the 1st Person Dual of the Imperative of रुह्( रुह् + शप् + वस् = रोह + आट् + वस्) 3.4.92 = रोहाव the स् being elided, as लोट् is like लङ् 3.4.85 and 3.4.99. The verb एहि is the 2nd Person Singular of the Imperative of the root इण्, preceded by the Particle आङ् ॥ Here in रोहाव एहि (= रोहाव आइहि), the verb रोहाव is followed by the Particle आ, and does not retain its accent. But for this rule, it would have retained its accent. Because एहि is a गत्यर्थ लोट् 8.1.51, रोहाव is another लोट् in connection with it, and therefore, by 8.1.52 it would have retained its accent. But now it loses its accent because it is a तिङ् following after a non तिङ् word स्वः ॥ It The visarga of स्वः is elided before र् by 8.3.14, then the preceding अ is lengthened and we have स्वा 6.3.111. Another reading is स्वो रोहावैहि ॥ It is a Vedic anomaly, the visarga is changed to उ ॥