BṚHADĀRAṆYAKA UPANISHAD · 2.4.3

सा होवाच मैत्रेयी -- येनाहं नामृता स्यां किम् अहं तेन कुर्याम् ।
यद् एव भगवान् वेद तद् एव मे ब्रूहीति ॥

sā hovāca maitreyī -- yenāhaṃ nāmṛtā syāṃ kim ahaṃ tena kuryām ।
yad eva bhagavān veda tad eva me brūhīti ॥

And Maitreyî said: 'What should I do with that by which I do not become immortal? What my Lord knoweth (of immortality), tell that to me.'

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