Once I gave a horse (for riding) in Allah's Cause. Later I saw it being sold. I asked Messenger of Allah ﷺ (whether I could buy it). He said, "Don't buy it, for you should not get back what you have given in charity."
عُمَرُ ؓ حَمَلْتُ عَلَى فَرَسٍ فِي سَبِيلِ اللَّهِ فَرَأَيْتُهُ يُبَاعُ فَسَأَلْتُ رَسُولَ اللَّهِ ﷺ فَقَالَ لاَ تَشْتَرِ وَلاَ تَعُدْ فِي صَدَقَتِكَ