Sadaqat al-Fitr (or Zakat al-Fitr) is prescribed by the Sharee‘ah based on the general indication of the texts of the Quran and the Sunnah, as well as by scholarly consensus. Allah The Almighty Says (what means): {He has certainly succeeded who purifies himself. And mentions the Name of his Lord and prays.} [Quran 87:14-15]
The Commander of the Believers, ‘Umar ibn ‘Abdul-Azeez would command the Muslims to give Sadaqat al-Fitr and recite the abovementioned verse. As for the Sunnah, Ibn ‘Umar said, "The Prophet ordained Zakat al-Fitr to be given as one Saa‘ (handful) of dates or barley for every slave and free Muslim, male or female, young or old. He ordered it to be given out before the Muslims go to the ‘Eed Prayer." [Al-Bukhari and Muslim]
The scholars have unanimously agreed on the obligation of Zakat al-Fitr, which has two stipulations:
1- Its amount (one Saa’) should be over and above one’s own need and the need of his dependants for the day and night of ‘Eed.
2- It should be given upon (and not before) the arrival of its due time, which is sunset of the last day of Ramadan.
Zakat al-Fitr is an individual obligation upon every Muslim who can afford it. It was ordained, along with fasting, in the second year after Hijrah (Prophetic emigration). The recipients of Sadaqat al-Fitr are the same recipients of general Zakah, based on what Allah The Almighty Says (what means): {Zakah expenditures are only for the poor and for the needy…} [Quran 9:60]
The amount to be given of Sadaqat al-Fitr is a single Saa‘ for each Muslim, but it can be less than one Saa‘ if the Muslim does not find any more than that. Sadaqat al-Fitr is obligatory upon every Muslim individually, and the Muslim is not obligated to give it on behalf of others according to the preponderant opinion of scholars. However, one can give it on behalf of those under his care with their consent. An exception to this ruling is the slave, for whom Sadaqat al-Fitr is, of course, an obligation, but in his case it is alright for his master to pay on his behalf. The Prophet said: "There is no charity to be paid on the slave (i.e. for owning him) except Sadaqat al-Fitr.” [Muslim]
It is recommended that the Muslim gives Sadaqat al-Fitr on behalf of the fetus if it becomes four months old as ‘Uthmaan did so, and he was one of the four Rightly-Guided Caliphs regarding whom we are ordered to follow their practices.
It is permissible to give Zakat al-Fitr early but only by a maximum of two days before ‘Eed as this was authentically reported from Ibn ‘Umar : In a Hadeeth, it was said, "Ibn ‘Umar gave Sadaqat al-Fitr for those who would accept it, and they used to receive it one or two days before ‘Eed al-Fitr." [Al-Bukhari] However, it is preferable to give it before the ‘Eed Prayer due to the Hadeeth which was narrated on the authority of Ibn ‘Umar where it was mentioned that the Prophet ordered Sadaqat al-Fitr to be distributed before Muslims go out for the ‘Eed Prayer. It is not permissible to delay it until after the ‘Eed Prayer, and if it is, it would not be valid. The Prophet said: “Whoever introduces something to our affairs (i.e. religion) which does not belong to it, it will be rejected.”
Therefore, the time for giving Zakat al-Fitr can be one of three:
1- Permissible: which is two days before ‘Eed al-Fitr
2- Recommended: which is the morning of the day of ‘Eed before the Prayer
3- Prohibited: which is after the ‘Eed Prayer, when it would not be valid
It is permissible for the Muslim to authorize someone to give it on his behalf. Also, there is no sin on him who delays giving it for a valid reason and therefore gives it late. Sadaqat al-Fitr can be given out of the common staple-food of the country, and according to the majority of scholars it is not permissible to give the monetary value of the Sadaqat al-Fitr. The Muslim may give one person many Saa‘s or one Saa‘ for many people.
Finally, it is preferable for the Muslim to give it personally so that he would be sure of delivering it to its due recipients on time.