Narrated 'Umar (RA):

I provided a man with a horse to ride in Allah's Cause, but as he did not look after it well, I thought he would sell it at a cheap price. I therefore asked Allah's Messenger (ﷺ) about that and he said, "Do not buy it even if he gives it to you for a Dirham..." The narrator reported the rest of the Hadith. [Agreed upon].

وَعَنْ عُمَرَ ‏- رضى الله عنه ‏- قَالَ : { حَمَلْتُ عَلَى فَرَسٍ فِي سَبِيلِ اَللَّهِ , فَأَضَاعَهُ صَاحِبُهُ , فَظَنَنْتُ أَنَّهُ بَائِعُهُ بِرُخْصٍ، فَسَأَلْتُ رَسُولَ اَللَّهِ ‏- صلى الله عليه وسلم ‏-عَنْ ذَلِكَ .‏ فَقَالَ : " لَا تَبْتَعْهُ , وَإِنْ أَعْطَاكَهُ بِدِرْهَمٍ … } اَلْحَدِيثَ.‏ مُتَّفَقٌ عَلَيْه ِ [1]‏ .‏