Approaching the end of his life, Abraham seeks to organize his family affairs and secure the continuity of his spiritual and material legacy. Parting from his other sons and transferring his entire inheritance to Isaac is not merely a legal transaction, but a historical decision that shapes the future of the nation, establishing a complete separation between the chosen son and the rest of the descendants. Since Abraham had already given Isaac everything he owned when sending his servant to find Isaac a wife, the primary approach among commentators is that this renewed giving is not a physical transfer of property. Rather, it functions as a deathbed will designed to grant permanent, absolute, and final validity to his earlier gifts [רש״י, גור אריה, משכיל לדוד, ברטנורא, ברכת אשר, דברי דוד]. On a deeper level, Abraham is passing down the Divine power to bless whomever he chooses, a unique capability God originally bestowed upon Abraham Himself [רש״י, מזרחי, גור אריה]. Practically, executing this transfer through a formal will is necessary because Abraham cannot relinquish all his assets while still alive; uncertain of who might pass away first, he might still need Isaac to support him [צאינה וראינה].
The decision to transfer the estate to a single son while disinheriting the others raises a significant legal and moral question, as standard practice forbids a father from diverting an inheritance even from a wicked son to a righteous one. Commentators justify Abraham's actions through both legal and Divine mandates. From a legal standpoint, Abraham and Ishmael are considered converts, and according to the law, a convert does not inherit from a convert father [הטור הארוך, רא״ש, פענח רזא, הדר זקנים, דעת זקנים]. Furthermore, this path relies on explicit Divine instruction. God previously agreed with Sarah's demand that the maidservant's son would not inherit, establishing that only Isaac is considered Abraham's legal and spiritual offspring regarding the inheritance [כלי יקר, העמק דבר, הטור הארוך, פענח רזא, רד״ק].
The totality of what Isaac receives encompasses several layers. In physical terms, Abraham gives Isaac all the wealth he earned through his own hard work and effort, whereas the sons of his concubines receive items Abraham was given by others, such as the gifts he acquired from the Egyptians on Sarah's account [כלי יקר]. In a broader sense, Isaac is granted the birthright, the blessing, the material assets, and complete mental and spiritual prosperity [מלבי״ם]. Spiritually, this inheritance represents Abraham's absolute share in the World to Come. Unlike material possessions that strangers can confiscate or destroy, eternal reward is the only thing that truly belongs to a person, and this is what Abraham ultimately passes down to Isaac [כלי יקר].
In stark contrast to Isaac's absolute inheritance, Abraham gives his other sons specific gifts and sends them away. This early separation during Abraham's lifetime is designed to prevent future conflicts and battles over the inheritance of the Land of Israel [רד״ק, מלבי״ם]. These gifts effectively serve as a legal severance, permanently blocking any future territorial claims the descendants of Ishmael and Keturah might bring against the nation of Israel [תורה תמימה]. Alongside this physical and legal separation, the gifts also carry a mystical nature. Abraham imparts esoteric knowledge to the sons of the concubines, allowing them to manipulate natural forces and astrology, purposefully directing them toward these practices to prevent them from engaging in the gross idolatry of household gods [הטור הארוך, מלבי״ם, ברטנורא]. Ultimately, this parting highlights a fundamental difference in their destinies. While Isaac inherits the World to Come, the other sons receive their compensation immediately in this world. By sending them eastward, Abraham pays out their physical share upfront, fulfilling Sarah's prophecy of an unequal inheritance and preserving the complete, eternal, and spiritual reward exclusively for Isaac [כלי יקר].