tan aksatan svastimato nisamya
sastrastra-pugair atha vrtra-nathah
drumair drsadbhir vividhadri-srngair
aviksatams tatrasur indra-sainikan
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the soldiers of the demons, commanded by Vrtrasura, saw that the soldiers of King Indra were quite well, having not been injured at all by their volleys of weapons, not even by the trees, stones and mountain peaks, the demons were very much afraid.