Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 15
नदत्सु यातुधानेषु जयकाशिष्वथो मृधे ।उदतिष्ठद्रथस्तस्य नीहारादिव भास्कर: ॥ १५ ॥
nadatsu yātudhāneṣujaya-kāśiṣv atho mṛdheudatiṣṭhad rathas tasyanīhārād iva bhāskaraḥ
The Yakṣas, being temporarily victorious, exclaimed that they had conquered Dhruva Mahārāja. But in the meantime Dhruva’s chariot suddenly appeared, just as the sun suddenly appears from within foggy mist.
Here Dhruva Mahārāja is compared to the sun and the great assembly of the Yakṣas to foggy mist. Fog is insignificant in comparison with the sun. Although the sun is sometimes seen to be covered by fog, in fact the sun cannot be covered by anything. Our eyes may be covered by a cloud, but the sun is never covered. By this comparison to the sun, the greatness of Dhruva Mahārāja in all circumstances is affirmed.