At that time Dhruva Mahārāja became perfectly aware of the Vedic conclusion and understood the Absolute Truth and His relationship with all living entities. In accordance with the line of devotional service to the Supreme Lord, whose fame is widespread, Dhruva, who in the future would receive a planet which would never be annihilated, even during the time of dissolution, offered his deliberate and conclusive prayers.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
स वै तदैव प्रतिपादितां गिरं दैवीं परिज्ञातपरात्मनिर्णयः । तं भक्तिभावोऽभ्यगृणादसत्वरं परिश्रुतोरुश्रवसं ध्रुवक्षितिः
sa vai tadaiva pratipāditāṃ giraṃ daivīṃ parijñātaparātmanirṇayaḥ | taṃ bhaktibhāvo'bhyagṛṇādasatvaraṃ pariśrutoruśravasaṃ dhruvakṣitiḥ
SB 4.9.5