Valmiki Ramayana Yuddha Kanda Sarga 67 Shloka 154

यैः by that, सायकैः arrows, सालवराः Sala trees, निकृत्ताः cut down, वानरपुङ्गवः Vanara leaders, वाली च Vali also, हतः struck, ते that, तदा then, वज्रोपमम् like thunderbolt, कुम्भकर्णस्यशरीरम् Kumbhakarna's body, न व्यधयांप्रचक्रुः not able to affect him.

Those arrows which had cut down the Sala trees and the Vanara leader, Vali, which were like thunderbolts, did not affect Kumbhakarna's body.