Prathama-prakaraṇam (Yama) · Verse 59
शुश्रूषैव तु शूद्रस्य ब्रह्मचर्यं प्रकीर्तितम् । शुश्रूषा वा गुरोर्नित्यं ब्रह्मचर्यमुदाहृतम् ॥
śuśrūṣaiva tu śūdrasya brahmacaryaṃ prakīrtitam | śuśrūṣā vā gurornityaṃ brahmacaryamudāhṛtam ||
For the śūdra, brahmacarya is defined as service (śuśrūṣā), and constant service to the guru is also called brahmacarya. This radical redefinition — service as celibacy — reflects the social framework where the śūdra’s dharma is service, and fulfilling that dharma with dedication is equivalent to the self-restraint required of other varṇas.