Valmiki Ramayana Yuddha Kanda Sarga 33 Shloka 22
Original Shlokaसन्नाहजननीह्येषाभैरवाभीरु: भेरिका । भेरीनादंचगम्भीरंशृणुतोयदनिःस्वनम् ।।6.33.22।।
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भीरु timid, भैरवा fear, एषा these, भेरिका of drums, सन्नाहजननीहि to let the army start, तोयदनिःस्वनम् sound of rain clouds, गम्भीरम् very penetrating, भेरीनादंच sound of drums, शृणु listen.
"O Timid Sita! Listen to the deep penetrating sounds of drums like the rumbling of rain clouds signifying the preparations of the army."