The maintenance of the father in his old age is the duty laid down for the son. This is the eternal Shruti (audition) current in the three worlds, O learned Rishi.
पुत्रार्थो विहितो ह्येष वार्धके परिपालनम्। श्रुतिरेषा हि विप्रर्षे त्रिषु लोकेषु शाश्वती॥