कौमाराद् यौवन चापि स्थावीर्य चापि यौवनात् | अनेन क्रमयोगेन पूर्व पूर्व न लभ्यते
kaumārād yauvanaṃ cāpi sthāvīryaṃ cāpi yauvanāt | anena kramayogena pūrvaṃ pūrvaṃ na labhyate ||
कौमाराद् यौवनं चापि स्थावीर्यं चापि यौवनात्। अनेन क्रमयोगेन पूर्वं पूर्वं न लभ्यते॥
भीष्य उवाच
Life moves in an irreversible sequence—childhood to youth to old age—so one should not postpone dharma, learning, restraint, and inner cultivation, since earlier capacities and opportunities do not return once lost.
In Śānti Parva, Bhīṣma instructs Yudhiṣṭhira on righteous living and wisdom after the war; here he emphasizes the one-way flow of time and the need to act rightly while one has strength and clarity.