Hadith on Charity: The Prophet has obligated payment of charity upon the end of Ramadan

Ibn Umar reported: The Messenger of Allah, peace be upon him, made it an obligation upon the people to pay Zakat Al-Fitr (charity upon breaking the fast) during the month of Ramadan, including every freeman and servant, male and female: a portion of dates or a portion of barely.

[Sahih Muslim, Book 5, Number 2149]

عَنْ ابْنِ عُمَرَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَرَضَ زَكَاةَ الْفِطْرِ مِنْ رَمَضَانَ عَلَى النَّاسِ صَاعًا مِنْ تَمْرٍ أَوْ صَاعًا مِنْ شَعِيرٍ عَلَى كُلِّ حُرٍّ أَوْ عَبْدٍ ذَكَرٍ أَوْ أُنْثَى مِنْ الْمُسْلِمِينَ

صحيح مسلم كتاب الزكاة باب زكاة الفطر على المسلمين من التمر والشعير