Queen Suruci told Dhruva Mahārāja: My dear child, you do not deserve to sit on the throne or on the lap of the King. Surely you are also the son of the King, but because you did not take your birth from my womb, you are not qualified to sit on your father’s lap.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
न वत्स नृपतेर्धिष्ण्यं भवानारोढुमर्हति । न गृहीतो मया यत्त्वं कुक्षावपि नृपात्मजः
na vatsa nṛpaterdhiṣṇyaṃ bhavānāroḍhumarhati | na gṛhīto mayā yattvaṃ kukṣāvapi nṛpātmajaḥ
SB 4.8.11