question #1 Sahih al-Bukhari 2971, Book 56, Hadith 180 : What is the ruling on buying back a gift that has been given as charity in Islam?

`Umar gave a horse to be used in Allah’s Cause, but later on he found it being sold. So, he intended to
buy it and asked Allah’s Messenger (ﷺ) who said, “Don’t buy it and don’t take back your gift of charity.”