ŚVETĀŚVATARA UPANISHAD · 1.7

उद्गीतम् एतत् परमं तु ब्रह्म तस्मिंस् त्रयं स्वप्रतिष्ठाक्षरं च ।
अत्रान्तरं ब्रह्मविदो विदित्वा लीना ब्रह्मणि तत्परा योनिमुक्ताः ॥

udgītam etat paramaṃ tu brahma tasmiṃs trayaṃ svapratiṣṭhākṣaraṃ ca ।
atrāntaraṃ brahmavido viditvā līnā brahmaṇi tatparā yonimuktāḥ ॥

But what is praised (in the Upanishads) is the Highest Brahman, and in it there is the triad. The Highest Brahman is the safe support, it is imperishable. The Brahma-students, when they have known what is within this (world), are devoted and merged in the Brahman, free from birth.

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