Valmiki Ramayana Sundara Kanda Sarga 43 Shloka 10

सहस्रशः in a thousand ways, शिलाभिः with rocks, पादपैश्च or even with trees, प्रहरतः hurling, मे to me, युद्धे in war, रावणसहस्रम् a thousand Ravanas, प्रतिबलम् match in might, तु also, न भवेत् not be.

'Not even a thousand Ravanas can stand my might in combat as I start assailing them with thousands of rocks or even trees.