It was proven from the Messenger of Allaah (peace and blessings of Allaah be upon him) that he enjoined zakaat al-fitr on the Muslims, one saa' of dates or one saa' of barley, and he commanded that it be given before the people went out to the (Eid) prayer. In al-Saheehayn it is narrated that Abu Sa'eed al-Khudri (may Allaah be pleased with him) said: At the time of the Prophet (peace and blessings of Allaah be upon him) we used to give one saa' of food, or one saa' of dates, or one saa' of barley, or one saa' of raisins.
Some of the scholars have interpreted food (ta'aam) in this hadeeth as referring to wheat; others interpreted it as meaning the staple food of the country, whatever it is, whether it is wheat, corn, pearl millet or whatever. This is the correct view, because zakaah is a help from the rich to the poor, and the Muslim does not have to help with anything other than the staple food of his country. Undoubtedly rice is the staple food in the land of the Two Holy Sanctuaries (Saudi Arabia) and it is a good and valuable food; it is better than the barley that is mentioned in the text. Hence it is known that there is nothing wrong with giving rice as zakaat al-fitr.
What must be given is a saa' of any kind of staple food, i.e., a saa' of the Prophet (peace and blessings of Allaah be upon him), which is four complete scoops as scooped up with two hands, according to al-Qaamoos etc. In modern weights this is equivalent to approximately three kilograms. If a Muslim gives a kilo of rice or some other staple food of his country, that is sufficient even if it is not one of the types mentioned in the hadeeth, according to the more correct of the two scholarly opinions. There is nothing wrong with giving the equivalent amount by weight, which is approximately three kilograms.
Zakaat al-fitr must be given on behalf of all Muslims, young and old, male and female, free and slave. With regard to a foetus, it is not obligatory to give it on his behalf according to scholarly consensus, but it is mustahabb, because Uthmaan (may Allaah be pleased with him) did that.
It is also obligatory to give it before the Eid prayer, and it is not permissible to delay it until after the Eid prayer. There is nothing wrong with giving it one or two days before the Eid. Hence it is known that the earliest time when it may be given, according to the more correct of the two scholarly views, is the night of the 28th of Ramadaan, because the month may be twenty-nine or thirty days. The companions of the Messenger of Allaah (peace and blessings of Allaah be upon him) used to give it one or two days before Eid.
Those to whom it must be given are the poor and needy. It was proven that Ibn Abbaas (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) enjoined zakaat al-fitr as a purification for the fasting person from idle and obscene speech, and to feed the poor. Whoever gives it before the prayer, it is zakaat al-fitr, and whoever gives it after the prayer, it is ordinary charity. This was narrated by Abu Dawood and classed as hasan by al-Albaani in Saheeh Abi Dawood.
It is not permissible to pay the value in money, according to the majority of scholars; this view has the stronger evidence. Rather it must be given in the form of food, as the Prophet (peace and blessings of Allaah be upon him) and his companions (may Allaah be pleased with them) did. This is also the view of the majority of the ummah. We ask Allaah to help us and all the Muslims to understand His religion properly and adhere to it steadfastly, and to guide us, for He is the Most Generous, Most Kind.
Majmoo' Fataawa al-Shaykh Ibn Baaz, 14/200.
This is the estimation of Shaykh Ibn Baaz (may Allaah have mercy on him), who reckoned the weight of zakaat al-fitr as being approximately three kilograms.
This was also the estimate of the scholars of the Standing Committee (9/371).
Shaykh Ibn Uthaymeen (may Allah have mercy on him) estimated it in grams as being 2100 grams, as it says in Fataawa al-Zakaah, p. 274-276.
This discrepancy occurred because a saa' is a measure of volume, not weight.
The scholars worked it out by weight so that it would be easier to work out. It is well known that the weight of grains varies; some are light and some are heavy, and some are in between. In fact the weight of a saa' of the same kind of grain may vary, and new may weigh more than old. Hence if people err on the side of caution and give more, that will be better.
See al-Mughni, 4/168, where it mentions something similar about working out the nisaab of crops by weight.
And Allaah knows best.
Reproduced from Islam QA