BṚHADĀRAṆYAKA UPANISHAD · 4.4.19

मनसैवानुद्रष्टव्यं नेह नानास्ति किं चन ।
मृत्योः स मृत्युम् आप्नोति य इह नानेव पश्यति ॥

manasaivānudraṣṭavyaṃ neha nānāsti kiṃ cana ।
mṛtyoḥ sa mṛtyum āpnoti ya iha nāneva paśyati ॥

'By the mind alone it is to be perceived, there is in it no diversity. He who perceives therein any diversity, goes from death to death.

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