Gave all that he had unto Isaac - His principal flocks, and especially his right to the land of Canaan, including a confirmation to him and his posterity of whatever was contained in the promises of God.

And Abraham gave all that he had unto Isaac. By his last will and testament; not all out of his own hand, while he lived, at least he reserved somewhat for himself, and for gifts to his other children; so his servant declared to the parents and friends of Rebekah, Genesis 24:35; wherefore some render the words here "had given" (d); or the sense is, that he had at that time purposed and promised to give all that he had to Isaac, and now he actually did it.
(d) "dederat", Junius & Tremellius, Piscator.

Abraham gave all that he had unto Isaac . . . unto the sons of the concubines . . . Abraham gave gifts--While the chief part of the inheritance went to Isaac; the other sons (Ishmael included) migrated to "the East country," that is, Arabia, but received each a portion of the patrimony, perhaps in cattle and other things; and this settlement of Abraham's must have given satisfaction, since it is still the rule followed among the pastoral tribes.

Before his death, Abraham made a final disposition of his property. Isaac, the only son of his marriage with Sarah, received all his possessions. The sons of the concubines (Hagar and Keturah) were sent away with presents from their father's house into the east country, i.e., Arabia in the widest sense, to the east and south-east of Palestine.

And Abraham gave all that he had to Isaac - As he was bound to do in justice to Sarah his first wife, and to Rebekah who married Isaac upon the assurance of it.