Midrasch zu Bereschit 24:36

Rabbi Simeon said: Our father Abraham wrote (in his will and bequeathed) all that he had as an inheritance to Isaac, as it is said, "And Abraham gave all that he had unto Isaac" (Gen. 25:5). He took the document and gave it into the hands of Eliezer, his servant, (who) said, Since the document is in my hand all his money is in my hand, so that he might go and be recommended (thereby) in his father's house and with his family.