Thirukkural 70

மகன்தந்தைக்கு ஆற்றும் உதவி இவன்தந்தை என்நோற்றான் கொல் எனும் சொல்.

Makan thanthaaikku aatrum utavi ivan thanthai ennotraan kol enum sol.

The son's service to his father is measured by one measure: what austerity did his own father endure? This is the measure of his duty.