Valmiki Ramayana Kishkindha Kanda Sarga 54 Shloka 14

पुरा earlier, अशनिम् a thunderbolt, क्षिपता by throwing, इन्द्रेण by Indra, स्वल्पम् a little, कृतं हि has done, लक्ष्मणः Lakshmana, निशितै: with sharp ones, बाणैः with arrows, पत्रपुटम् यथा like tearing a leaf cup, भिन्द्यात् he can shatter.

'In the past Indra had done a small damage (to the cave) with his thunderbolt. But with his sharp arrows Lakshmana will shatter the cave easily as though it is a leaf cup.