आचारप्रशंसा
Praise of Ācāra as the Basis of Longevity, Fame, and Prosperity
संध्यायां न स्वपेद् राजन् विद्यां न च समाचरेत्
saṁdhyāyāṁ na svaped rājan vidyāṁ na ca samācaret
ભીષ્મે કહ્યું— હે રાજન! સંધ્યાકાળે ન સૂવું અને તે સમયે વિદ્યાનો અભ્યાસ-આચરણ પણ ન કરવું.
भीष्म उवाच
Twilight (sandhyā) is treated as a liminal, disciplined time meant for prescribed observances; therefore one should avoid sleeping then and also avoid taking up study/learning activities at that junction.
In the Anuśāsana Parva’s instruction section, Bhīṣma continues advising the king (Yudhiṣṭhira) on proper conduct (ācāra), giving a specific rule about what should not be done during sandhyā-time.