Ramayana
उत्तरं च न वक्तव्यं शूर वाक्यान्तरे मम । बालेन पूर्वजस्याज्ञा कर्तव्या नात्र संशयः ॥ 7-62-20 ॥
"And no reply is to be made, O hero, in answer to my words. By a younger one the command of an elder must be carried out; in this there is no doubt."
english translation