sāvitraṁ prājāpatyaṁ ca
brāhmaṁ cātha bṛhat tathā
śiloñcha iti vai gṛhe
sāvitram—the thread ceremony of the twice-born; prājāpatyam—to execute the vow for one year; ca—and; brāhmam—acceptance of the Vedas; ca—and; atha—also; bṛhat—complete abstinence from sex life; tathā—then; vārtā—vocation in terms of Vedic sanction; sañcaya—professional duty; śālīna—livelihood without asking anyone for cooperation; śila-uñchaḥ—picking up rejected grains; iti—thus; vai—even though; gṛhe—in household life.
Then the thread ceremony for the twice-born was inaugurated, as were the rules to be followed for at least one year after acceptance of the Vedas, rules for observing complete abstinence from sex life, vocations in terms of Vedic injunctions, various professional duties in household life, and the method of maintaining a livelihood without anyone’s cooperation by picking up rejected grains.
During student life the brahmacārīs were given full instructions about the importance of the human form of life. Thus the basic education was designed to encourage the student in becoming free from family encumbrances. Only students unable to accept such a vow in life were allowed to go home and marry a suitable wife. Otherwise, the student would remain a permanent brahmacārī, observing complete abstinence from sex life for his whole life. It all depended on the quality of the student’s training. We had the opportunity to meet an avowed brahmacārī in the personality of our spiritual master, Oṁ Viṣṇupāda Śrī Śrīmad Bhaktisiddhānta Gosvāmī Mahārāja. Such a great soul is called a naiṣṭhika-brahmacārī.
Link to this page: https://prabhupadabooks.com/sb/3/12/42