brahma-kṣatriya-viṭ-śūdrā varṇās tv ādyās trayo dvijāḥ |
(Yājñavalkya Smṛti: 1.10)
“Brāhmaṇa, kṣatriya, vaiśya, and śūdra are the varṇas. The first three, however, [i.e., but not the fourth, the śūdras] become twice-born (dvija).”
saṁskārā yatrāvicchinnāḥ sa dvijo’jo jagāda yam |
(Śrīmad Bhāgavatam: 7.11.13)
“He in regard to whom the saṁskāras are uninterrupted and whom the Unborn One [viz., Brahmādeva] has mentioned [i.e., designated to be such] is a twice-born (dvija).”
dvitīyaṁ prāpyānupūrvyāj janmopanayanaṁ dvijaḥ |
vasan guru-kule dānto brahmādhīyīta cāhutaḥ ||
(Śrīmad Bhāgavatam: 11.17.22)
“After receiving in sequence the second birth, the upanayana [-saṁskāra], and being invited [by a guru], a twice-born (dvija) should dwell in the house of the guru, be disciplined, and study the Veda.”
mātur yad agre jāyante dvitīyaṁ mauñji-bandhanāt |
brāhmaṇa-kṣatriya-viśas tasmād ete dvijāḥ smṛtāḥ ||
(Yājñavalkya Smṛti: 1.39)
“Since they are born first from a mother [i.e., by way of seminal birth] and second by the tying of mauñji [i.e., the upanayana-saṁskāra, which involves a ritual in which mauñji, a type of cane grass, is tied as a girdle around the initiate’s waist], these brāhmaṇas, kṣatriyas, and vaiśyas are known as the twice-born (dvijas).”
mātur agre’dhi-jananaṁ dvitīyaṁ mauñji-bandhane |
tṛtīyaṁ yajña-dīkṣāyāṁ dvijasya śruti-codanāt ||
(Manu Smṛti: 2.169)
“As per the precept of the Śruti, a twice-born’s birth is first from a mother, second by the tying of mauñji [i.e., the upanayana-saṁskāra, which involves a ritual in which mauñji, a type of cane grass, is tied as a girdle around the initiate’s waist], and the third by yajña-dīkṣā [i.e., initiation into performance of Vedic sacrifice].”
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].”
