Mahabharata 12.307.2

तपसा वा सुमहता कर्मणा वा श्रुतेन वारसायनप्रयोगैर्वा कैर्नोपैति जरान्तकौ

tapasā vā sumahatā karmaṇā vā śrutena vārasāyanaprayogairvā kairnopaiti jarāntakau

Our plain-language meaning of this verse is waiting for scholar review.