Bukhari :: Book 3 :: Volume 47 :: Hadith 804

Narrated 'Umar bin Al-Khatab:

Once I gave a horse (for riding) in Allah's Cause. Later I saw it being sold. I asked Allah's Apostle (whether I could buy it). He said, "Don't buy it, for you should not get back what you have given in charity."

Source materials are from the University of Southern California MSA site
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