Sahih Muslim — The Book of Oaths — Hadith No: 4263
Translation
Abu Musa al-Ash'ari reported:I came to Allah's Apostle (ﷺ) along with a group of Ash'arites requesting to give us a mount. He (the Holy Prophet) said: By Allah, I cannot provide you with a mount, and there is nothing with me which I should give you as a ride. He (the narrator) said: We stayed there as long as Allah willed. Then there were brought to him (to the Holy Prophet) camels. He (the Holy Prophet) then ordered to give us three white humped camels, We started and said (or some of us said to the others): Allah will not bless us. We came to Allah's Messenger (ﷺ) begging him to provide us with riding camels. He swore that he could not provide us with a mount, but later on he provided us with that. They (some of the Prophet's Companions) came and informed him about this (rankling of theirs), whereupon he said: It was not I who provided you with a mount, but Allah has provided you with that. So far as I am concerned, by Allah, if He so wills, I would not swear, but if, later on, I would see better than it, I (would break the vow) and expiate it and do that which is better