Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 103.14

103.14

taddharanti suputrāśca vaitaraṇyāṃ gatānapi /
putreṇa lokāñjayati pautreṇa paramā gatiḥ //

good sons deliver them, even those who have entered into the Vaitaraṇī.
Through a son one conquers the worlds; through a grandson [one attains] the supreme goal;