Valmiki Ramayana Sundara Kanda Sarga 53 Shloka 41
Original Shlokaस भूत्वा शैलसङ्काशः क्षणेन पुनरात्मवान्।।5.53.41।। ह्रस्वतां परमां प्राप्तो बन्धनान्यवशातयत्।
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आत्मवान् assumed original form, सः that, शैलसङ्काशः appearing like a mountain, भूत्वा becoming, क्षणेन in a moment, ह्रस्वताम् very small, प्राप्तः became, बन्धनानि all bondage, अवशातयत् casting off.
From his mountainlike form he assumed his original small figure within a moment casting off the bonds.