Musnad Ahmad Hadith 20189

It is narrated from Samurah (may Allah be pleased with him) that the Prophet (ﷺ) said: The seller and the buyer (the one who sells and the one who buys) have the option (to cancel the sale) as long as they do not separate from each other, and each of them can take what he is pleased with in the sale. Thalabah bin Abad Abdi says: One day I was present at the sermon of Samurah (may Allah be pleased with him), so he mentioned this hadith in his sermon referring to the Prophet (ﷺ), saying: One day, I and an Ansari boy were practicing archery during the blessed era of the Prophet (ﷺ). When, in the eyes of the onlookers, the sun had risen to the height of two or three spears, it suddenly became dark as if the grass of Tanumah had turned black. Then the narrator mentioned the entire hadith.