Targum zu Bereschit 15:2

And Abram said, Lord God, great blessings hast Thou given me, and great (are they which it is) before Thee to give me: nevertheless, what profit is to me, when I pass from the world without children, and Eliezer the manager (bar pharnasath, the son of sustenance) of my house, by whose hands signs were wrought for (or to) me in Darmasek, expects to be my heir?

And Abram said, Before Thee I supplicate mercy, O Lord God. Manifold blessings Thou hast given me, and many hast Thou before Thee still to give: nevertheless, what profit have I who go from the world childless, and Eliezer, the son of my house, by whose hands signs were wrought for me in Damasek, expecteth in himself to be my heir?