Ibn ’Abbas (RAA) narrated, ‘The Messenger of Allah (ﷺ) enjoined Zakat-ul-fitr on the one who fasts (i.e. fasted during the month of Ramadan) to purify him from any indecent act or speech and for the purpose of providing food for the needy. It is accepted as Zakah for the person who pays it before the Eid prayer and it is Sadaqah (i.e. voluntary charity) for the person who pays it after the Eid prayer.’ Related by Abu Dawud and Ibn Majah and Al-Hakim graded it as Sahih.

وَعَنِ اِبْنِ عَبَّاسٍ رَضِيَ اَللَّهُ عَنْهُمَا قَالَ: { فَرَضَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-زَكَاةَ اَلْفِطْرِ; طُهْرَةً لِلصَّائِمِ مِنَ اَللَّغْوِ, وَالرَّفَثِ, وَطُعْمَةً لِلْمَسَاكِينِ, فَمَنْ أَدَّاهَا قَبْلَ اَلصَّلَاةِ فَهِيَ زَكَاةٌ مَقْبُولَةٌ, وَمَنْ أَدَّاهَا بَعْدَ اَلصَّلَاةِ فَهِيَ صَدَقَةٌ مِنَ اَلصَّدَقَاتِ.‏ } رَوَاهُ أَبُو دَاوُدَ, وَابْنُ مَاجَهْ, وَصَحَّحَهُ اَلْحَاكِم ُ [1]‏ .‏