Sahih al-Bukhari, Book 24, Hadith 92 (In-Book) ⓘ
Narrated Abu Huraira: Al-Hasan bin `Ali took a date from the dates given in charity and put it in his mouth. The Prophet said, "Expel it from your mouth. Don't you know that we do not eat a thing which is given in charity?"
حَدَّثَنَا آدَمُ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا مُحَمَّدُ بْنُ زِيَادٍ، قَالَ سَمِعْتُ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ أَخَذَ الْحَسَنُ بْنُ عَلِيٍّ ـ رضى الله عنهما ـ تَمْرَةً مِنْ تَمْرِ الصَّدَقَةِ، فَجَعَلَهَا فِي فِيهِ، فَقَالَ النَّبِيُّ صلى الله عليه وسلم " كِخٍ كِخٍ ـ لِيَطْرَحَهَا ثُمَّ قَالَ ـ أَمَا شَعَرْتَ أَنَّا لاَ نَأْكُلُ الصَّدَقَةَ " .
also referenced under: Hadith 1491 (DarusSalam) & Volume 2, Book 24, Hadith 568 (USC-MSA)