Jñāneśvarī (commentary on the Bhagavadgītā) 1.243

1.243

kulakṣaye praṇaśyanti kuladharmāḥ sanātanāḥ
dharme naṣṭe kulaṃ kṛtsnam adharmo 'bhibhavaty uta
jaiseṃ kāṣṭheṃ kāṣṭha mathije |
tetha vanhi eka upaje |
teṇeṃ kāṣṭhajāta jāḷije |
prajvaḷaleni ||

Just as when one piece of wood is rubbed against another, / a fire is produced between them, / and blazing up, it burns down / all the wood that is there,