Āśrama-dharma: Duties of the Four Life-Stages (आश्रमधर्मः)
यं च कज्चिद् द्विजातीनां शूद्र: शुश्रूषुराव्रजेत्
yaṃ ca kaścid dvijātīnāṃ śūdraḥ śuśrūṣur āvrajet
และหากศูทรผู้มุ่งหมายจะปรนนิบัติด้วยความเคารพ เข้าไปหาใครผู้หนึ่งในหมู่ทวิชะ…
भीष्म उवाच
The verse frames a dharmic scenario in which a Śūdra, motivated by śuśrūṣā (respectful service and attendance), approaches a member of the twice-born classes; it introduces norms of conduct centered on service, humility, and social duty.
In Śānti Parva, Bhīṣma is instructing Yudhiṣṭhira on dharma. Here he begins a conditional statement about a Śūdra who approaches a dvijāti with the intention to serve, setting up the rule or consequence that follows in the subsequent verse(s).