Zakah is generally a compulsory tax on Muslims to the needy in the society. It is a fundamental pillar of islam.
Zakatul Fitri is obligatory upon every Muslim who is self-supporting, if he has one saa’ or more than he needs of food for himself and his family on the day and night of Eid.
The basis for that is the report narrated from a companion of Prophet Muhammad, Abdullah Ibn ‘Umar (may Allaah be pleased with him) who said:
“The Messenger of Allaah (peace and blessings of Allaah be upon him) enjoined zakaat al-fitr, a saa’ of dates, or a saa’ of barley, upon all the Muslims, slave and free, male and female, young and old, and he commanded that it be paid before the people went
out to pray.” [Bukhari]
And Abu Sa’eed al-Khudri narrated: “We used to pay zakaat al-fitr when the Messenger of Allaah (peace and blessings of Allaah be upon him) was alive, a saa’ of food or a saa’ of dates or a saa’ of barley or a saa’ of raisins or a saa’ of dried yoghurt.”
It is acceptable to give a saa’ of the local staple food such as rice etc.
What is meant by a saa’ here is the saa’ of the Messenger of Allaah (peace and blessings of Allaah be upon him), which is four times the amount that may be held in the two hands of a man of average build. If a person does not pay zakaat al-fitr, he is sinning, and he has to make it up.
This zakah must also the paid before the eid prayer, as this will make the recipient of the zakah attend the
prayer elated.