The Companions (may Allah be pleased with them) said: We wished that Sayyiduna Uthman and Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with them both) would trade with each other, so that we could see which of them was the greater merchant. Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) bought from Sayyiduna Uthman (may Allah be pleased with him) a horse that was in another place, for forty thousand dirhams or about that. He said: If the horse is found safe and sound after the deal, then the deal stands. Then, after going a little way, he came back. Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) said: I will give six thousand dirhams more, if my messenger finds it safe and sound. He said: Yes. Then the messenger of Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) found it dead, and Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) was released (from the deal) by that second condition.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10423