Chandogya Upanishad 8.7.3

8.7.3

tau ha dvātriṃśataṃ varṣāṇi brahmacaryam ūṣatuḥ \
tau ha prajāpatir uvāca \
kim icchantāv avāstam iti \
tau hocatur ya ātmā apahatapāpmā vijaro vimṛtyur viśoko vijighatso 'pipāsaḥ satyakāmaḥ satyasaṃkalpaḥ so 'nveṣṭavyaḥ sa vijijñāsitavyaḥ \
sa sarvāṃś ca lokān āpnoti sarvāṃś ca kāmān yas tam ātmānam anuvidya vijānātīti bhagavato vaco vedayante \
tam icchantāv avāstam iti \\807.3\

3. Then for thirty-two years the two lived the chaste life of a student of sacred knowledge (brahmacarya).

Then Prajāpati said to the two: 'Desiring what have you been living?'

Then the two said: '"The Self (Ātman), which is free from evil, ageless, deathless, sorrowless, hungerless, thirstless, whose desire is the Real, whose conception is the Real—He should be searched out, Him one should desire to understand. He obtains all worlds and all desires who has found out and who understands that Self."'—Such do people declare to be your words, Sir. We have been living desiring Him.'