Valmiki Ramayana Yuddha Kanda Sarga 96 Shloka 39
Original Shlokaतेषांतुरथघोषेणराक्षसानांमहात्मनाम् । वानराणामपिचमूर्युद्धायैवाभ्यवर्तत ।।6.96.39।।
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महात्मनाम् great, तेषांराक्षसानाम् those Rakshasas, रथघोषेण sound of chariots, वानराणाम् Vanaras, चमूःअपि army troops also, युद्धायैव for the sake of battle, अभ्यवर्तत stood facing.
The Vanaras stood facing the great sound of Rakshasa troops, on hearing the sounds of chariots for the sake of battle.