CHĀNDOGYA UPANISHAD · 6.7.5

तं होवाच ।
यथा सोम्य महतो ऽभ्याहितस्यैकम् अङ्गारं खद्योतमात्रं परिशिष्टं तं तृनैर् उपसमाधाय प्राज्वलयेत् तेन ततो ऽपि बहु दहेत् ॥

taṃ hovāca ।
yathā somya mahato ’bhyāhitasyaikam aṅgāraṃ khadyotamātraṃ pariśiṣṭaṃ taṃ tṛnair upasamādhāya prājvalayet tena tato ’pi bahu dahet ॥

'As of a great lighted fire one coal of the size of a firefly, if left, may be made to blaze up again by putting grass upon it, and will thus burn more than this,