Daiva Chintanam is the greatest Sadhana. You should give utmost satisfaction to your parents. Consider it as your bounden duty to offer water to your parents at the time of their passing away. You should touch their feet and pay obeisance to them everyday. Having been born as a son or a daughter to them, you have to do your duty and show respect to your parents. Only then will you attain fulfilment in life. Even when you are not seeing your parents physically, you should feel that they are with you. After their departure from the world, you perform the rite of tarpanam to them (ceremony in memory of the parents). What is true tarpanam? Performing the formal ritual of feeding Brahmins is not enough. You should shed tears of gratitude. Remembrance of your parents with gratitude is the most important thing that you should do. This is the greatest act of punya (merit). (SSS Vol.36)