Bhagavad Gita 12.5

क्लेशोऽधिकतरस्तेषामव्यक्तासक्तचेतसाम्।अव्यक्ता हि गतिर्दुःखं देहवद्भिरवाप्यते ॥१२.५॥

kleśo’dhikatarasteṣāmavyaktāsaktacetasāmavyaktā hi gatirduḥkhaṃ dehavadbhiravāpyate

Greater is their trouble whose minds are set on the unmanifested, for the goal of the unmanifested is very hard for the embodied to reach.

गीता