द्रव्ययज्ञास्तपोयज्ञा योगयज्ञास्तथापरे।
स्वाध्यायज्ञानयज्ञाश्च यतयः संशितव्रताः।।4.28।।
श्रीमद् भगवद्गीता
4.28 द्रव्ययज्ञाः those who offer wealth as sacrifice, तपोयज्ञाः those who offer austerity as sacrifice, योगयज्ञाः those who offer Yoga as sacrifice, तथा thus, अपरे others, स्वाध्यायज्ञानयज्ञाः those who offer study and knowledge as sacrifice, च and, यतयः ascetics or anchorites (persons of selfrestraint), संशितव्रताः persons of rigid vows.
Commentary:
Some do sacrifice by distributing their wealth to the deserving as charity some offer their Tapas (austerities) as sacrifice some practise the eight limbs of Raja Yoga, viz., Yama (the five great vows), Niyama (the canons of conduct), Asana (posture), Pranayama (restraint of breath), Pratyahara (withdrawal of the senses), Dharana (concentration), Dhyana (meditation) and Samadhi (superconscious state), and offer this Yoga as a sacrifice some study the scriptures and offer it as sacrifice.