Bava Metzia page 48b.rav chia bar joseph had salt to sell. someone gave him partial [payment. then the price of salt went up. Rav Chiya came to R Yochanan and asked if he could retrack on the deal. R. Yochanan said he has to keep the deal, because R Yochanan held a partial payment acquires the whole purchase [the goods need to be delivered and the remaing payment needs to be paid.]. Rav said it acquires only up to its amount. my question here is where is the picking up? for even though money acquires from the law of the Torah, however the sages decreed no deal is final until the bought object is picked up. so in our case let me ask. where is the picking up?--------------------IN בבא מציעא page מ''ח ע''ב there is a case where ר' חייא בר יוסף had salt to sell. Someone gave him partial payment ערבון . Then the price of salt went up. רב חייא came to ר' יוחנן and asked if he could retrack on the deal. ר' יוחנן said he has to keep the deal, because ר' יוחנן held a partial payment acquires the whole purchase [the goods need to be delivered and the remainder of payment needs to be paid.]. But, רב said it acquires only up to its amount. My question here is where is the picking up? for even though money acquires from the law of the תורה, however the sages decreed no deal is final until the bought object is picked up. So, in our case let me ask. where is the picking up? The salt was not picked up and yet the sale is considered to be final.