I was riding a camel of mine when it grew exhausted, so I decided to set it loose. The Messenger of Allah ﷺ caught up with me, struck the camel with his foot, and prayed for it. It then walked at a pace unlike any it had ever walked before.He said, "Sell it to me for an ounce of silver."I was reluctant to sell it.He said again, "Sell it to me."So I sold it to him, on the condition that I could ride it back to my family. When we arrived, I brought the camel to him.He said, "Did you think, when I bargained with you, that I would actually take your camel? Take your camel and the price as well. Both are yours."
حدثنا يحيى بن سعيد عن زكريا حدثني عامر
كنت أسير على جمل لي فأعيا فأردت أن أسيبه قال فلحقني رسول الله ﷺ فضربه برجله ودعا له فسار سيرا لم يسر مثله وقال بعنيه بوقية فكرهت أن أبيعه قال بعنيه فبعته منه واشترطت حملانه إلى أهلي فلما قدمنا أتيته بالجمل فقال ظننت حين ماكستك أن أذهب بجملك خذ جملك وثمنه هما لك
Its isnad is sahih, and Amir is Ibn Sharahil Shaybi, the imam. Zakariya is Ibn Zaidah, also an imam. The hadith appears in all six sahih collections. See Bukhari 3/248, in the chapter on testimony, if the seller stipulates riding the animal's back. Similarly in Muslim, in the chapter on sales.