Is it obligatory to take possession of the goods when buying and selling gold?

Question : The questioner says: I offered some gold pieces to one of the shops, and at the same time I bought a set of gold of high value. Then I asked for the total value after deducting what I sold from the purchase price, so I gave him the amount, and he gave me what I sold to him, and gave me the remainder. However, the exchange of possession did not take place for the price of the item sold. This happened out of my ignorance, so what is the ruling?

Answer : If it has passed and ended, and there was no condition between them that you sell to him and buy from him, then there is nothing wrong with it. But if there was a condition between them, she must return the item sold if possible and cancel the first transaction.