परिभ्रमितचेतसः with a whirling mind, तस्य of that Dasaratha, तथा in that way, विलपतः lamenting सूर्यः the Sun, अस्तमभ्यगमत् set, रजनी च night also, अभ्यवर्तत च fell.

While Dasaratha was thus lamenting with a distracted mind, the Sun set and night fell.