Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 34: Satyavatī, Viśvāmitra’s Elder Sister
Text 1.34.15

निष्पन्दास्तरवः सर्वे निलीना मृगपक्षिणः।
नैशेन तमसा व्याप्ता दिशश्च रघुनन्दन॥

niṣpandās taravaḥ sarve nilīnā mṛga-pakṣiṇaḥ
naiśena
tamasā vyāptā diśaś ca raghu-nandana

niṣpandāḥ = are motionless; taravaḥ = the trees; sarve = all; nilīnāḥ = have gone to sleep; mṛga-pakṣiṇaḥ = the deer and bird; naiśena = of night; tamasā = of darkness; vyāptāḥ = are pervaded; diśaḥ ca = all directions; raghu-nandana = O beloved son of Raghus.

All the trees are motionless. The deer and birds have gone to sleep. O beloved son of the Raghus, all directions are pervaded by the darkness of night.

The four verses beginning with this describe the beginning of night. The trees are motionless because the birds don’t move on them. The directions are pervaded by the darkness of night, that is, that portion of night just after dusk.