Srimad-Bhagavatam: Canto 5 - Chapter 1 - Verse 5
तत्रगतो दंशमशकसमापसदैर्मनुजै: शलभशकुन्ततस्करमूषकादिभिरुपरुध्यमानबहि:प्राण: क्वचित् परिवर्तमानोऽस्मिन्नध्वन्यविद्याकामकर्मभिरुपरक्तमनसानुपपन्नार्थं नरलोकं गन्धर्वनगरमु पपन्नमिति मिथ्यादृष्टिरनुपश्यति ॥ ५ ॥
tatra gato daṁśa-maśaka-samāpasadair manujaiḥ śalabha-śakunta-taskara-mūṣakādibhir uparudhyamāna-bahiḥ-prāṇaḥ kvacit parivartamāno ’sminn adhvany avidyā-kāma-karmabhir uparakta-manasānupapannārthaṁ nara-lokaṁ gandharva-nagaram upapannam iti mithyā-dṛṣṭir anupaśyati.
Sometimes the conditioned soul in household life, being attached to material wealth and possessions, is disturbed by gadflies and mosquitoes, and sometimes locusts, birds of prey and rats give him trouble. Nonetheless, he still wanders down the path of material existence. Due to ignorance he becomes lusty and engages in fruitive activity. Because his mind is absorbed in these activities, he sees the material world as permanent, although it is temporary like a phantasmagoria, a house in the sky.
The following song is sung by Narottama dāsa Ṭhākura: Due to forgetting the lotus feet of Lord Nityānanda and being puffed up by material possessions, wealth and opulence, one thinks the false, temporary material world to be an actual fact. This is the material disease. The living entity is eternal and blissful, but despite miserable material conditions, he thinks the material world to be real and factual due to his ignorance.