Aashiash: Swami Ji Namaskar, In Hindu Dharma after death usually for one year or for lifetime “Water etc” is offered to “Pitra” by Sons. I want to know why all this and what is logic behind it. THANKS
Swami Ram Swarup: My blessings to you. To offer water or do Shradh etc., is man-made custom. Vedas never tell about it. In this connection, I paste my article below:-

Shradh can never be performed in any case being unauthentic and illegal. Shradh means to serve the parents by all means i.e., with food, by protecting them, caring for them, providing them with clothes while they are alive because the meaning of Shradh is faith/believe. When soul goes out of body, at the time of death then dead body is burnt on pyre and soul based on his deeds (good or bad) takes another birth after thirteen days of death. Now, we must think how a person can do Shradh i.e., can make a departed soul to eat, take clothes etc., (Chapter 39 of Yajurveda refers).

Anna Daan/Shradh to departed soul

Vedas are eternal knowledge which emanate direct from God at the beginning of every universe. Being the knowledge direct from God, each statement of Ved mantra is also eternal truth.

Thirty-ninth chapter of Yajurveda states about death. The soul when leaves the human body remains under control of a divine air named “Sutratma vayu”. Mantras tell that after wandering unconsciously for thirteen days in the space and planets like Sun, moon, etc., soul comes again on this earth inside the vegetation. Then either the soul enters the male living being’s body according to pious deeds and sins through pores or is duly mixed within vegetation and taken by a male person. Then the soul takes rebirth through parents.

This process is an eternal truth. However, if soul is religious and has done hard tapasya then the soul gets salvation. Only soul has to face the result of previous lives’ deeds through living being’s body. Since soul is alive whereas body is non-alive matter. So body does not face the result of deeds. When soul has gone out of body then how the soul will see, hear, taste, smell or touch or will be benefited of any pious deed etc.? therefore Vedas do not tell about the present system of shradh etc.

However, the pious deeds done to remember the departed soul by means of devotion or organising the holy Yajyen with Ved mantras, its result never goes in vain and the family is benefited.

Departed soul never meets again please. Even departed soul, when take rebirth, forgets every event of his previous life. As regards dreams Atharvaveda states that dreams of departed soul are not good so it is in your interest and welfare that you do not see dreams.

Ashwin: Swamiji, my pranams to you. I heard that in living beings, there is prana vaayu which is necessary to be alive. Then what is the necessity of soul in the living beings. Does soul also enter the body along with the prana vaayu while taking birth and they both leave at the time of death. Please clarify me.
Swami Ram Swarup: My blessings to you.

Prann vaayu is required for our physique only and not for soul. You see, whenever body would be healthy and stable/functioning then only soul would reside in the body.

Yes, soul enters the body along with sukshma (subtlest) prann vaayu and not with sthool prann vayu.

Deepak: SWAMIJI CHARAN SPARSH THANKS for always give me blessings. I am happy after I came to meet you..please bless me if I can do something for you, as I know without your wish no one can do anything …
Swami Ram Swarup: My blessings to you my son Deepak.