Musa bin Talha reported,

A rabbit that a man had roasted was brought to the Prophet ﷺ. When the man presented it to him, he said, "Messenger of Allah, I noticed that it had blood on it."The Messenger of Allah ﷺ left it and did not eat from it. He said to those with him, "Eat, for had I desired it, I would have eaten it."A man was sitting there, and the Messenger of Allah ﷺ said to him, "Come closer and eat with the people."The man replied, "Messenger of Allah, I am fasting."He said, "Why did you not fast the white days?"The man asked, "What are they?"He said, "The thirteenth, the fourteenth, and the fifteenth."

Nasai 2431

Sahih

أخبرنا محمد بن إسمعيل بن إبراهيم قال حدثنا يعلى عن طلحة بن يحيى

عن موسى بن طلحة قال

أتي النبي ﷺ بأرنب قد شواها رجل فلما قدمها إليه قال يا رسول الله إني قد رأيت بها دما فتركها رسول الله ﷺ فلم يأكلها وقال لمن عنده كلوا فإني لو اشتهيتها أكلتها ورجل جالس فقال رسول الله ﷺ ادن فكل مع القوم فقال يا رسول الله إني صائم قال فهلا صمت البيض قال وما هن قال ثلاث عشرة وأربع عشرة وخمس عشرة

النسائي 2431صحيح
Contents
Reference
Commentary
Ayat
Collection
Sunan Nasai Sughra
Book
Fasting
Chapter
Difference of opinion regarding Musa bin Talha in the report about fasting three days of the month
Numbering
Darussalam 2431
Nasai 2431