JB, 1, 159, 5.0 tasmād uṣṇiho jaghanārdhe 'kṣarāṇi bhūyiṣṭhāni //

PB, 8, 5, 2.0 uṣṇikkakubbhyāṃ vā indro vṛtrāya vajraṃ prāharat kakubhi parākramatoṣṇihā prāharat tasmāt kakubho madhyamaṃ padaṃ bhūyiṣṭhākṣaraṃ parākramaṇaṃ hi tad abhisamauhat tasmād uṣṇiha uttamaṃ padaṃ bhūyiṣṭhākṣaraṃ puro gurur iva hi vajraḥ //