An Imperative preceded by a preposition and not in the 1st person, following an Imperative of verbs of 'motion', may optionally retain its accent when the kāraka is not wholly different.,
The whole of the preceding sutra is understood here. This is a Prapta-vibhasha. Thus आगच्छ देवदत्त ग्रामं प्रविश꣡ or प्र꣡वि॒॒श॒॒ ॥ आगच्छ देवदत्त ग्रामं प्रशाधि꣡ or प्र꣡शा॒॒धि॒॒ ॥ When the verb is accented, the upasarga loses its accent by 8.1.71.
Why do we say सोपसर्गं 'joined with a Preposition'? When there is no Preposition, there is no option allowed, and the last rule will apply. As आगच्छ देवदत्त ग्रामं पश्य ॥
Why do we say अन्-उत्तमं 'not a First Person'? Observe आ गच्छानि देवदत्त, ग्रामं प्रवि॒॒शा꣡नि॒॒ ॥,