Manava Dharmashastra 3.121

Manvarthamuktāvalī 3.121

utthāya sarvadā vṛddhābhivādanaśīlasya vṛddhasevinaśca āyuḥprajñāyaśobalāni catvāri samyak prakarṣeṇa vardhante|
saṃpratyabhivādanavidhimāha—