vaithinaatha deekshideeyam is the scriptural reference for all pitru karmas. taken from from vedas by experts .
on 12th day itself the your father got the pitru as vasu swaroopam.
the great maharishis like aapasthambar, bhodaayanar, aashvalayanar, drahyayanar have without self interest, prescribed under the name Apara suthram the various rituals and the basis on which these rituals are based to enable soul of the deceased to attain a good status.
Brahma yagyam must be done daily after madhyanikam after upanayanam is over until death. no till is required for brahmayagyam. you are doing brahmayagyam to the devas, rishis and to the care takers of pithrus.
pithrus means parents, forefsathers who have lived with us in this world as part of our family and who have paased away during the course of time. pithrus are gender neutral.
sastras say that when an individual dies, the jeevan in his body leaves it, to enter into another body. The same is stated by Lord krishna in bhagwad geetha.
An individual changes his/her clothes after a while, in a similar fashion the jeevan too discards the current body.when it becomes old and sick.and enters into another body.
The jeevan from the dead body does not posses enough energy to travel to pitruloka on its own.
Hence to enable it to go to pitru loka Aparakarmas have to be done with utmost sincerity.
Garuda puranam and Upanishads indicate that there is no birth or death to the jeevan. This pitru loka is also called as yamalokam.
The jeevan spends its time in the pitru loka based on its merits accumulated in its earlier births.
When the jeevan enters the court of yama dharma raja the jeevan is questioned in front of yamadharmaraja and in the presence of twelve jurors and Chithragupthan as witnesses
There are 12 witnesses in dharmaraja sabha for the good and bad deeds performed by an individual in that world.
What are the good merits and bad merits done . When, how many times. What were the effects of these deeds. . Should the jeevan reside in swaga or in hell. Where the jeevan should born again. What type of birth.
The results of the good and bad deeds are analyzed and accordingly the jeevan is sent to other worlds to experience these results or to another body.
Our human body is called pancha boutigam. .It has been created out of the 5 elements earth, empty space or ether or aakaash, water, fire and air.
These five elements are always present in the human body. The same five elements are there in devas, gandharva, rakshasha, four legged animals, creepers, trees, birds, fish, serpants etc. but the proportion of these elements varies.
The proportion of earth element is high in human body. This immortal soul, or atman or jeevan which is the source and support for all the pranas, mind,intellect, senses, and the body abides in the chamber”s of one”s heart.
As this body has been cremated , a new body has to be created and through that structure the jeevan has to be sent to paraloka. The body structure is required for the jeevan to experience various emotions like happiness grief etc.
our sastras and maharishis through their medidative and yogic powers have elaborated methods on how to create a new body structure for the jeevan to use after its death.
The symbolic body structure is created thru mantras, offerings of pindams, and bali done as part of the daily samskaras. While making these offerings the Gothra of the deceased has to be mentioned.
Thru the nithya vidhi karma and the pinda offerings made every day the jeevan gets head on the first day.
2nd day eyes, ears, and nose; third day hands, breast and neck. 4th day navel and stomach.
5th day thighs, 6th day skin; 7th day nervous system, 8th day bodily hairs, 9th day energy.
On the tenth day the jeevan gets urge for food and happiness . This is stated by Rushya sringa maharishi.
The main purposes of all these karmas are to assist the jeevan to reach the paraloka with ease.
When some one dies , the karma done on 11th day for the good of the deceased is vrishabhothsarjanam. Based on the cremation day as the first day. And not by treating the death day as the first day.
On the 11th day it will be treated as preatha swaroopam and first masikam must be done on 11th day.
On 12th day during sapindeekaranam the dead person is mingling with your pithrus.
From 12th day itself he /she is attaining pithru swaroopam,as vasu swaroopam, And the aadhithya swaroopa of your father”s grand father will be given curd rice, in a new towel and he is going from aadithya swaroopam.