Sahih al-Bukhari 3003
صحيح البخاري#3003SahihNarrated Aslam:I heard `Umar bin Al-Khattab saying, "I gave a horse to be ridden in Allah's Cause and the person who got it intended to sell it or neglected it. So, I wanted to buy it as I thought he would sell it cheap. I consulted the Prophet (ﷺ) who said, "Do not buy it even if for one Dirham, because he who takes back his gift is like a dog swallowing its vomit
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 56:212