SB 4.9.25

tato gantāsi mat-sthānaṁ
 sarva-loka-namaskṛtam
upariṣṭād ṛṣibhyas tvaṁ
 yato nāvartate gataḥ
Synonyms: 
tataḥ — thereafter; gantā asi — you will go; mat-sthānam — to My abode; sarva-loka — by all planetary systems; namaḥ-kṛtam — offered obeisances; upariṣṭāt — situated higher; ṛṣibhyaḥ — than the planetary systems of the ṛṣis; tvam — you; yataḥ — wherefrom; na — never; āvartate — will come back; gataḥ — having gone there.
Translation: 
The Personality of Godhead continued: My dear Dhruva, after your material life in this body, you will go to My planet, which is always offered obeisances by the residents of all other planetary systems. It is situated above the planets of the seven ṛṣis, and having gone there you will never have to come back again to this material world.
Purport: 

In this verse the word nāvartate is very significant. The Lord says, “You will not come back to this material world, for you will reach mat-sthānam, My abode.” Therefore Dhruvaloka, or the polestar, is the abode of Lord Viṣṇu within this material world. Upon it there is an ocean of milk, and within that ocean there is an island known as Śvetadvīpa. It is clearly indicated that this planet is situated above the seven planetary systems of the ṛṣis, and because this planet is Viṣṇuloka, it is worshiped by all other planetary systems. It may be questioned here what will happen to the planet known as Dhruvaloka at the time of the dissolution of this universe. The answer is simple: Dhruvaloka remains, like other Vaikuṇṭhalokas beyond this universe. Śrīla Viśvanātha Cakravartī Ṭhākura has commented in this connection that the very word nāvartate indicates that this planet is eternal.