Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 17

Sanskrit:

धृष्टाद् धार्ष्टमभूत् क्षत्रं ब्रह्मभूयं गतं क्षितौ ।नृगस्य वंश: सुमतिर्भूतज्योतिस्ततो वसु: ॥ १७ ॥

ITRANS:

dhṛṣṭād dhārṣṭam abhūt kṣatraṁbrahma-bhūyaṁ gataṁ kṣitaunṛgasya vaṁśaḥ sumatirbhūtajyotis tato vasuḥ

Translation:

From the son of Manu named Dhṛṣṭa came a kṣatriya caste called Dhārṣṭa, whose members achieved the position of brāhmaṇas in this world. Then, from the son of Manu named Nṛga came Sumati. From Sumati came Bhūtajyoti, and from Bhūtajyoti came Vasu.

Purport:

Here it is said, kṣatraṁ brahma-bhūyaṁ gataṁ kṣitau: although the Dhārṣṭas belonged to the kṣatriya caste, they were able to convert themselves into brāhmaṇas. This gives clear evidence supporting the following statement by Nārada (Bhāg. 7.11.35): If the qualities of one group are found in the men of another, those men should be recognized by their qualities, by their symptoms, not by the caste of the family in which they were born. Birth is not at all important; it is one’s qualities that are stressed in all Vedic literature.