Ramayana
यदि तावच्छिशोरस्य त्वीदृशो गतिविक्रमः । यौवनं बलमासाद्य कथं वेगो भविष्यति ॥ 7-35-27 ॥
If even as an infant his speed and prowess in flight are such as this, then what will his velocity become once he attains the strength of youth?
english translation