Abu Darda reported,

Darda reported from the Prophet ﷺ that Allah granted His Messenger some camels as spoils, which he distributed.Abu Musa said, "Messenger of Allah, give me a mount."He replied, "No." Abu Musa repeated his request three times.The Prophet ﷺ then said, "By Allah, I will not do it."Then four camels with white humps were brought, and he said, "Abu Musa, take them."Abu Musa said, "Messenger of Allah, I asked you for a mount and you refused, and you swore an oath. I feared that some displeasure had entered the Messenger of Allah ﷺ against me."He answered, "When I swear an oath and then see that something else is better, I make expiation for my oath and do what is better."

Azami 7104

Sahih

عن أبي

الدرداء، عن النبي ﷺ قال: أفاء الله على رسوله إبلا. ففرقها. فقال أبو موسى: يا رسول الله احملني. فقال: لا فقاله ثلاثا. فقال النبي ﷺ: والله لا أفعل وبقي أربع غر الذرى. فقال: يا أبا موسى خذهن فقال: يا رسول الله إني استحملتك فمنعتني وحلفت. فأشفقت أن يكون دخل على رسول الله ﷺ وهم. فقال: إني إذا حلفت فرأيت أن غير ذلك أفضل كفرت عن يميني، وأتيت الذي هو خير.

الأعظمي 7104صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Oaths and vows
Chapter
Faith
Section
Exception in oaths
Numbering
Jami al-Kamil 7104 (2nd edition)
Azami 7104