Sunan Abi Dawud 1593
سنن أبي داود#1593SahihNarrated ‘Abdallah bin Umar :‘Umar bin Al Khattab gave a horse as alms in the way of Allah. He then found it being sold, and intended to buy it. So he asked the Messenger of Allah (ﷺ) about this. He said Do not buy it, and do not take back your sadaqah
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (2636) Sahih Muslim (1620)
In-book reference: 9:38