Pṛthivī-dohaṇa (The Milking of the Earth) and the Praise of King Pṛthu
ज्यैष्ठ्यकानिष्ठ्यमप्येषां पूर्वमासीद्द्विजोत्तमाः / तप एव गरीयो ऽभूत्प्रभावश्चैव कारणम्
jyaiṣṭhyakāniṣṭhyamapyeṣāṃ pūrvamāsīddvijottamāḥ / tapa eva garīyo 'bhūtprabhāvaścaiva kāraṇam
O best of the twice-born, in former times there was even a distinction of elder and younger among them; yet tapas alone was weightier, and its potency was the cause.