Matsyapurana 32.40

32.40

*śukra uvāca
saṃkrāmayiṣyasi jarāṃ yatheṣṭaṃ nahuṣātmaja
māmanudhyāya tattvena na ca pāpamavāpsyasi //

Śukra said :—“By my favour, O King! You will exchange your old age with youth without committing any sin; and any of your sons, willingly giving you his youth in exchange for your old age, will certainly be blessed with many children and will be illustrious and long-lived.”—40-41.