Āśrama-dharma: Duties of the Four Life-Stages (आश्रमधर्मः)
यं च कज्चिद् द्विजातीनां शूद्र: शुश्रूषुराव्रजेत्
yaṃ ca kaścid dvijātīnāṃ śūdraḥ śuśrūṣur āvrajet
Bhīṣma said: “And if any Śūdra, intent on respectful service, should approach one of the twice-born (Brāhmaṇa, Kṣatriya, or Vaiśya)…”
भीष्म उवाच