Valmiki Ramayana Yuddha Kanda Sarga 29 Shloka 9
Original Shlokaआचार्यागुरवोवृद्धावृथावांपर्युपासिताः । सारंयद्राजशास्त्राणामनुजीव्यंनगृह्यते ।।6.29.9।।
1 source checked for this shloka
यत् that which is, राजशास्त्राणाम् in political sastras, अनुजीव्यम् living upon, सारम् essence, नगृह्यते not grasped, वाम् both of you, आचार्य teachers, गुरव sages, वृद्धा parents, वृथा waste, पर्युपासिता waiting upon.
"You have not grasped that which is the essence of political wisdom in the sastras in spite of waiting upon elders, teachers and parents which was in vain."