(4) Originally the Temple service was the charge of the firstborn – until it was given to the Tribe of Levi in their stead. God likewise grants the firstborn son an extra portion (Abarbanel ibid.). (3) Firsts are always beloved to God, such as the first fruits (which are brought to the Temple) and the firstborn animals. The firstborn demonstrates that his father is capable of having children and serves as a constant reminder that the family line will continue (Abarbanel Deut. (2) A father naturally loves his eldest son most since he views him as his continuity. The firstborn is also credited with making his father into a father thus, he has a special role in the family (R. It was thus natural to give him a larger portion of the family estate.
(1) The oldest son would naturally take over the family’s affairs with the father’s passing.
There are a number of suggested reasons for this: The Torah accords a higher status to the firstborn son ( bechor) – giving him a double portion of his father’s inheritance, and initially putting the Temple service in the hands of the firstborns – until later that service was given to the Priests in their stead.
