Valmiki Ramayana Ayodhya Kanda Sarga 59 Shloka 10
Original Shlokaन च सर्पन्ति सत्त्वानि व्यासा न प्रचरन्ति च। रामशोकाभिभूतं तन्निष्कूजमभवद्वनम्।।2.59.10।।
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सत्त्वानि living beings, न च सर्पन्ति are not moving, व्यालाः च wild animals also, नप्रचरन्ति not ranging, तत् वनम् that forest, रामशोकाभिभूतम् overpowered by grief on account of Rama, निष्कूजम् silent, अभवत् became.
No living being move about and even wild animals roam no more. Overwhelmed with grief on account of Rama a great silence pervades the forest.