Bhagavad Gita 4.28
Others offer as their sacrifice wealth, austerities, and meditation. Monks, wedded to their vows, renounce their scriptural learning and even their spiritual powers.
द्रव्ययज्ञास्तपोयज्ञा योगयज्ञास्तथापरे।
स्वाध्यायज्ञानयज्ञाश्च यतयः संशितव्रताः॥dravyayajñāstapoyajñā yogayajñāstathāpare|
svādhyāyajñānayajñāśca yatayaḥ saṃśitavratāḥ||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).