जन्मना ब्राह्मणो ज्ञेयः संस्कारैर्द्विज उच्यते ।
विद्यया याति विप्रत्वं त्रिभिः श्रोत्रियलक्षणम् ॥
janmanā brāhmaṇo jñeyaḥ saṁskārair dvija ucyate |
vidyayā yāti vipratvaṁ tribhiḥ śrotriya-lakṣaṇam ||
(Yājñavalkya; cited in Laghu Vaiṣṇava-toṣaṇī-ṭīkā and Vaiṣṇavānandinī-ṭīkā on Śrīmad Bhāgavatam: 10.16.2)
“One is to be known as a brāhmaṇa by birth. One is called a twice-born by saṁskāras. One attains vipratva [i.e., the status of being a vipra, a learned person] by learning. The characteristic of a śrotriya [i.e., one who is conversant in the Veda] is by these three [i.e., one who is born in a brāhmaṇa family, receives the necessary saṁskāras, and attains the necessary learning is accepted as being śrotriya, that is, conversant in the Vedas].”
Commentary
Another verse of almost extract the same import is cited in the Śabda-kalpa-druma and attributed to Padma Purāṇa:
janmanā brāhmaṇo jñeyaḥ saṃskārair dvija ucyate |
vidyābhyāsī bhaved vipraḥ śrotriyas tribhir eva hi ||
“One is to be known as a brāhmaṇa by birth. One is called a twice-born by saṁskāras. One cultivating knowledge shall be [accepted as] a vipra [i.e., a learned person]. A śrotriya [i.e., one who is conversant in the Veda] is verily only by these three [i.e., only one who is born in a brāhmaṇa family, receives the necessary saṁskāras, and attains the necessary learning is accepted as being śrotriya, that is, conversant in the Vedas].”