The moment a person dies, those who are the heirs according to Jewish law immediately become joint owners of the deceased’s estate. If, for example, the deceased had five sons and died intestate, without leaving a will, immediately upon his death and without further ado his five sons automatically become partners in the deceased’s estate.
The estate requires administration. One of the partner heirs must take charge. He must pay the debts of the estate. He must collect receivables due to the estate, invest on behalf of the estate to preserve its value, distribute the returns of the investment among the partner heirs, and sell assets of the estate to pay for current expenses. Ultimately, he must dissolve the partnership and divide the estate equitably among the heirs.
Generally it is the bechor, the firstborn son, who is given this responsibility.
There is an old saying in England: The salary of a judge should be sufficiently high that he would never be tempted to take a bribe.
Since it is generally the bechor who is appointed administrator over the estate, The Torah elevates him economically above his sibling heirs so that he should not be tempted to shortchange them in connection with the administration of the estate. To the contrary, the bechor should be incentivized to maximize the value of the estate for all the heirs and to deal fairly with them. The Torah achieves this by allocating the bechor a double portion in the estate compared to his brothers. This double portion is the bechor’s management fee.
In our example of the five brothers, the estate would be divided into six equal portions as if there were six brothers. The four brothers born after the bechor would receive one-sixth each and the bechor would receive one-third, or double the portion of each of his brothers. With the right to receive a double portion of the estate comes the obligation to pay a double portion of the debts of the estate. The bechor may, if he desires, waive the right to the double portion, in which case he would be relieved of the obligation to pay a double portion of the debts.
The firstborn who is eligible for the double portion of a father’s estate is the firstborn son, not a daughter. If the deceased only had daughters, the firstborn daughter would not receive a double portion in the father’s estate. There is, however, one circumstance in which a daughter may receive a double portion. That is the situation where her father was a bechor who died before his own father and was not survived by sons. In that situation, the daughter would inherit her father’s right, as a bechor, to a double portion in her grandfather’s estate.
The bechor is entitled to a double portion in the estate of his father but not to a double portion in the estate of his mother.
The firstborn son who is eligible for the double portion is the son first born to the father, not the first son born to the mother. Accordingly, if the father married a widow with five sons, who then bore him a son, this son is deemed the bechor for the purpose of the double portion. He is the firstborn son of the father even though he is not the firstborn son of the mother.
In this respect, the definition of a bechor for the purpose of inheritance differs from the definition of a bechor for the purpose of pidyon haben, the ceremony of redeeming the firstborn son. For the purpose of pidyon haben, the bechor is the peter rechem, the firstborn son of the mother.
In order to be entitled to a double portion, the bechor must have been born during his deceased father’s lifetime. A child born to his father posthumously is not a bechor for the purpose of a double portion. Neither is a child born by means of a caesarian procedure.
The right of the bechor to a double portion is restricted to assets that belong to the estate at the time of the father’s death. The right does not extend to future rights of the estate. Thus, for example, the bechor has no right to a double portion in an uncollected debt owing to the estate, because as long as it is outstanding, a debt is considered a future right of the estate.
A father may not transfer the bechor’s right to a double portion to a younger son. Any such attempt would be transgressing the words of the Torah and – would be void. How then was Jacob able to transfer the right of the firstborn from Reuven to Joseph and bequeath to Joseph a double portion in the Land of Israel?
One answer, suggested by the Midrash, is that Jacob’s firstborn should, by rights, have issued from Rachel, not Leah. It was only due to Rachel’s altruism in allowing Leah to be married to Jacob first that Reuven, the firstborn of Leah was the firstborn of Jacob. It would not be fair to penalize Rachel for this act of generosity – motivated as it was by her desire to save Leah the embarrassment of rejection – by denying Joseph the right to a double portion.