The article examines two Aramaic contracts found on the island Elephantine and dating from the early fifth century B.C. The first one is a loan contract providing for payment of compound interest on silver lent: interest not paid timely is to be added to the capital and itself becomes interest-bearing at the same rate until actual repayment. If this is not done at an agreed date, the remaining debt is doubled. The second contract concerns delivery of barley and lentils from a ship to a royal store-house deserving a garrison. The parties are the ship-officer and functionaries acting on behalf of the store-house, where barley and lentils are supposed to be brought. It is a contract of delivery combining its acceptation on the ship and the foreseen completion of the contract in the store-house with expected financial results. Both contracts refer to silver “by the stone-weights of Ptah” and record its alloy.