Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 25-26

Sanskrit:

अजानन्त: प्रतिविधिं तूष्णीमासन् सुरेश्वरा: ।ततो वैकुण्ठमगमद् भास्वरं तमस: परम् ॥ २५ ॥यत्र नारायण: साक्षान्न्यासिनां परमो गति: ।शान्तानां न्यस्तदण्डानां यतो नावर्तते गत: ॥ २६ ॥

ITRANS:

ajānantaḥ prati-vidhiṁtūṣṇīm āsan sureśvarāḥtato vaikuṇṭham agamadbhāsvaraṁ tamasaḥ param

Translation:

The great demigods could only remain silent, not knowing how to counteract the benediction. Then Lord Śiva reached the luminous realm of Vaikuṇṭha, beyond all darkness, where the Supreme Lord Nārāyaṇa is manifest. That realm is the destination of renunciants who have attained peace and given up all violence against other creatures. Going there, one never returns.

Purport:

According to Śrīla Śrīdhara Svāmī, Lord Śiva entered the planet of Śvetadvīpa, a special outpost of the spiritual world within the confines of the material universe. There, on a beautiful white island surrounded by the celestial Ocean of Milk, Lord Viṣṇu rests on the serpent bed of Ananta Śeṣa, making Himself available to the demigods when they need His help.