Canto 3 -
Araṇya-kāṇḍa
Chapter 48: Sītā-devī Condemns Rāvaṇa
Text 3.48.5

यद्भयार्तः परित्यज्य स्वमधिष्ठानमृद्धिमत्।
कैलासं पर्वतश्रेष्ठमध्यास्ते नरवाहनः॥

yad-bhayārtaḥ parityajya svam adhiṣṭhānam ṛddhimat
kailāsaṁ parvata-śreṣṭham adhyāste nara-vāhanaḥ

yat-bhaya-ārtaḥ = afflicted by fear of me; parityajya = gave up; svam = his; adhiṣṭhānam = city of residence; ṛddhimat = prosperous; kailāsam = in Kailāsa; parvata-śreṣṭham = the best of mountains; adhyāste = and resides; nara-vāhanaḥ = Kuvera.

Afflicted by fear of me, Kuvera gave up his prosperous city of residence and resides in Kailāsa, the best of mountains.1

It is implied that Kuvera resided in Kailāsa for support and strength.1

1 Rāmāyaṇa-bhūṣaṇa: nara-vāhanaḥ kuveraḥ. Kuvera is referred to as one whose vehicle is a human being.

1 He knew that Rāvaṇa wouldn’t attack him in Kailāsa, Lord Śiva’s abode. We will learn more about Rāvaṇa’s history in Canto 7 of the Rāmāyaṇa.