Ramayana
एष शापवशादेव न वेद बलमात्मनः । वालिसुग्रीवयोर्वैरं यदा राम समुत्थितम् ॥ 7-36-41 ॥
Through the power of a curse alone, O Rama, he does not know his own strength — even at the time when the enmity between Vali and Sugriva had arisen.
english translation