Anything which is used as payment for another [object], once this one takes possession —- that one becomes liable for its exchange. How? [If one] exchanged an ox for a cow, or a donkey for an ox, once this one takes possession —- that one becomes liable for its exchange.  Possession by the Temple treasury is with money, and possession by a private person is with an act of possession. Its oral dedication to the Temple is like its delivery to a private person.