The male child

Children in Cochin (Kerala - India)

Having a male child is necessary, indispensable for the salvation from damnation.
In India it is especially important, I would say essential, to have a son. To understand the reasons underlying this requirement is not sufficient to refer to aspects of an economic nature. No doubt, as we have seen in this previous post, a daughter means higher costs and lower benefits from an economic point of view, but it is necessary to analyze the motives of religious nature.
One day we will talk about hell, better about the hells of Hinduism, now it suffices  to say that a soul, stripped of the body after death and before of the reincarnated in another body will suffer the consequences of actions in 'heaven' or hell. After you have enjoyed or suffered for the actions in these lokas (place) the soul is reincarnated into another living being.
To avoid ending up in hell is first necessary to be conducted properly funeral ceremonies and is also necessary to be recited daily prayers for the ancestors. This is one of the three debts men must pay in this life, as well as to the gods and the sages to, everyone has a debt to the ancestors who must be worshiped and fed. The main protagonist of these ceremonies, these rituals and prayers of these is the male child.
"This debt - A. Danielou says in "The four ways of life"- can not be paid to creating a child who can continue the lineage, race, caste, family."
Not for nothing 'son' is said in Sanskrit putra, whose etymology goes back to the put, which is a type of hell, and traye, which in Sanskrit means to save, to preserve. The son is putra,  'He who saves from hell'.
This conviction brings with it many consequences. For example, in the Laws of Manu, the Manusmirti, the most important treaty on standards of behavior, it clearly states that women were created for boys and men to have offspring (Manusmirti IX, 96) and also provides that the husband can 'replace' the wife after eight years of marriage if the wife is infertile, after ten years of marriage if the wife has given birth children died, after eleven years if the wife has given birth only daughters (Manusmirti IX, 81).
Even in the choice of the woman to marry, Manu invites men to reject women from families with no sons, and that even if these families are "full of cows, goats, sheep, wheat, or property" (Manusmirti II, 7).
It is so important to have a son that Manu (IX, 174) considers it legitimate for a married man without sons can buy one for securing the funeral rites.
In the absence of sons, a grandson will perform the duties prescribed for his grandfather.
And  father on his deathbed whispers to son: "You are Brahman, you are the sacrifice, you are the world". The son replies, "I am Brahman, I'm the sacrifice, I am the world" (Brhadaranyaka Upanishad 5, 17).
And is the son who, after three laps counterclockwise around the pyre of his dead father, sets fire during the cremation rites.