Significance of immersing the ashes
Why Hindus Immerse Ashes of the Dead in the Holy River?
I am dividing the article in two parts. The first part is General/religious reason and the second part is Actual/spiritual reason.
GENERAL/RELIGIOUS REASON
Cremation is an extremely important ritual for Hindus. Generally it is stated that by immersing the ashes of dead person it releases an individual’s spiritual essence from its transitory physical body so it can be reborn. If it is not done or not done properly, it is thought; the soul will be disturbed and not find its way to its proper place in the afterlife and come back and haunt living relatives. The second reason given is by immersing the ashes of the dead, the soul gets salvation or Moksha, as all his sins are received by the holy river, & he given moksha. Holiest river by Hindus It is understood that when the ashes are immersed into the Holy Ganges or any of the big holy rivers, all the sins are pardoned; the dead will never return to the cycle of births and rebirths and will attain Heaven.
ACTUAL/SPIRITUAL REASON
The physical body is made up of five elements. On death, air departs, then heat, then water and finally earth remains for burying or burning in fire.
Sky exists ever and everything exists and happens in the sky. By burying, the body parts become part of earth. After burning, the ashes remain. The ancients believe that the Jeevatma (individual soul identifying the physical body and subtle body (mind, intellect, ego) continue to have attachment with the ashes (after burning the body) and when the ashes are immersed in rivers separate identity is lost.
Hindu cremation ceremony is intended to dissolve the material bond (attachment) between the Atman (soul) and the physical body so that the Atman can have a smooth transition to the astral world, upon the death of the physical body. The Atman develops attachment with the physical body during its life on earth and its transition to the astral world upon the death of the physical body becomes a painful affair. The cremation ceremony, Hindu cremation services also provides psychological healing to the mourners of the departed soul.
As water is all-assimilating, it imbibes the distressing vibrations remaining from the dead body in the ashes and the other Absolute Cosmic elements related to the subtle body like Absolute Earth, Fire, Air element etc. This helps to break the remaining attachment of the subtle body to its physical body on Earth. As a result, the probability of the subtle body getting stuck in the Earth plane reduced.
Source: Speaking Tree
Runanubandha
I am sure most of you have heard of runanubandha, which indicates a physical relationship. Whenever you touch someone – either because of blood relationship or sexual relationships, or even if you just hold someone’s hand or exchange clothes – these two bodies will generate runanubandha, a certain commonality. When someone dies, traditionally, you are seeing how to completely obliterate the runanubandha. The idea of putting the ashes in the Ganga or in the ocean is to disperse them as widely as possible so that you do not develop runanubandha with one who has departed. For you to continue your life, you must properly break this runanubandha. Otherwise, as it happens in modern societies, it will affect your physical and mental structure. Children up to eight years of age are immune to these things – nature has given them that protection, but adolescents will suffer immensely when we do not take care of the dead properly, because the energies of disembodied beings are always there and the first ones that they go after are adolescents because they are the most vulnerable. You see in the world today how much upheaval people are going through during adolescence.
One of the reasons why adolescence is more of a struggle today than it was in previous generations is that we are not properly taking care of those who have departed and these runanubandhas are all over the place. It is like loose software everywhere, and it always affects adolescent life most.
Source: Sadhguru (Isha Yoga)