यथाहनि तथा रात्रौ यथा रात्रौ तथाहनि । वशे तिष्ठति सत्त्वात्मा सततं योगयोगिनाम्,जो अपने मनमें चिन्तित कर्मजनित रजोगुणका अर्थात् रजोगुणजनित काम आदिका योगबलसे परित्याग कर देते हैं तथा जो प्रकृतिके तादात्म्यभावसे भी मुक्त हैं, उन सभी योगपरायण योगी पुरुषोंका जीवात्मा जैसे दिनमें वैसे रातमें, जैसे रातमें वैसे दिनमें सोते- जागते समय निरन्तर उनके वशमें रहता है
yathāhani tathā rātrau yathā rātrau tathāhani | vaśe tiṣṭhati sattvātmā satataṃ yogayoginām ||
Vyāsa said: For those yogins devoted to Yoga, whose inner being is governed by sattva, the self remains continually under their control—by day as by night, and by night as by day. In waking and in sleep alike, their disciplined awareness does not fall under the sway of restless desire; steadiness and mastery persist without interruption.
व्यास उवाच
True yogic discipline is continuous: the purified self (sattvātmā) remains under one’s mastery equally in day and night, in waking and sleeping, indicating stable freedom from agitation and desire.
Vyāsa is describing the hallmark of accomplished yogins in the Śānti Parva’s instruction: their inner self does not fluctuate with external conditions or time; it abides steadily under control at all times.