Mahabharata 12.308.120
कौमाराद्यौवनं चापि स्थाविर्यं चापि यौवनात्अनेन क्रमयोगेन पूर्वं पूर्वं न लभ्यते
kaumārādyauvanaṃ cāpi sthāviryaṃ cāpi yauvanātanena kramayogena pūrvaṃ pūrvaṃ na labhyate
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book