A man asked the Prophet ﷺ to provide him with a mount, but he found him preoccupied and said, "By Allah, I will not give you a mount."When the man turned to leave, the Prophet ﷺ called him back and provided him with a mount.The man said, "Messenger of Allah, you swore that you would not give me a mount."He replied, "I will break my oath and give you a mount."
استحمل النبي ﷺ فوافق منه شغلا فقال: والله لا أحملك فلما قفا دعاه فحمله فقال: يا رسول الله، إنك حلفت أن لا تحلمني، قال: فأنا أخلف لأحملنك.
Reported by Ahmad (12056), Bazzar in Kashf Astar (1344), and Abu Yaala (3835), all of them through the hadith of Humayd Tawil, from Anas, that Abu Musa... [and he related it]. Its chain of transmission is sahih.As for his saying, "I will swear an oath and still carry you," it means, "I will atone for my oath and carry you." This is a summary, and its details are as given in the previous hadith.