Hadith 2616
Chapter 100: Buying Something That One Has Given In Charity - كتاب الزكاة
أَخْبَرَنَا هَارُونُ بْنُ إِسْحَاقَ، قَالَ حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنْ مَعْمَرٍ، عَنِ الزُّهْرِيِّ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِيهِ، عَنْ عُمَرَ، أَنَّهُ حَمَلَ عَلَى فَرَسٍ فِي سَبِيلِ اللَّهِ فَرَآهَا تُبَاعُ فَأَرَادَ شِرَاءَهَا فَقَالَ لَهُ النَّبِيُّ صلى الله عليه وسلم " لاَ تَعْرِضْ فِي صَدَقَتِكَ " .
It was narrated from 'Umar that:
he gave someone a horse to ride in the cause of Allah, then he saw it offered for sale and wanted to buy it. The Prophet said to him: "Do not think of buying back what you have given in charity."
Reference : Sunan an-Nasa'i 2616
In-book reference : Book 23, Hadith 182