ŚVETĀŚVATARA UPANISHAD · 3.10

ततो यद् उत्तरतरं यद् अरूपम् अनामयम् ।
य एतद् विदुर् अमृतास् ते भवन्ति अथेतरे दुःखम् एवापियन्ति ॥

tato yad uttarataraṃ yad arūpam anāmayam ।
ya etad vidur amṛtās te bhavanti athetare duḥkham evāpiyanti ॥

That which is beyond this world is without form and without suffering. They who know it, become immortal, but others suffer pain indeed.

F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)