Musannaf Ibn Abi Shayba 13:208

'Abbad ibn al-'Awwam narrated to us, from Ash'ath, from al-Hakam, regarding a man who bought goods from a man, and they perished in the possession of the seller before he (the buyer) took possession of them. He said: If he had said to him, "Take your goods," and he did not take them, then they are in the possession of the seller from the buyer's wealth. And if he had said, "I will not hand them over to you until you bring the price," then they are the seller's wealth.