Umar once gave a horse to be used in the cause of Allah, and the Messenger of Allah ﷺ entrusted it to a man. Later, Umar came to the Messenger of Allah ﷺ and said, "I would like to buy back the horse I had donated."The Messenger of Allah ﷺ replied, "Do not buy it, and do not take back what you have given in charity."
حدثنا محمد بن عبيد حدثنا عبيد الله عن نافع
أن عمر حمل على فرس في سبيل الله فأعطاه رسول الله ﷺ رجلا فجاء عمر إلى رسول الله ﷺ فقال أبتاع الفرس الذي حملت عليه فقال لا تبتعه ولا ترجع في صدقتك
No references are available.
Its isnad is sahih, and it is a repetition of 5177.