I say, and with Allah's success: Zakat al-Fitr is obligatory under the following conditions:

First: Islam; Zakat al-Fitr is not obligatory on a non-Muslim, because there is no way to impose it in the case of disbelief, as it carries the meaning of worship and cannot be fulfilled without intention, and the non-Muslim is not among those who worship.

Second: Freedom; Zakat al-Fitr is not obligatory on a slave, because obligation is the obligation of performance, and there is no way to impose performance on a slave, as the slave is not required to perform it at the moment or after emancipation. It is impossible to impose an action that cannot be performed at all, unlike a wealthy child; if his guardian does not give it, he is obliged to perform it because he is capable of performing it after reaching maturity.

Third: Wealth; Zakat al-Fitr is not obligatory on the poor; as narrated by Abu Huraira: 'There is no charity except from a position of wealth' in Sahih al-Bukhari 2: 518, and in another wording: 'The best charity or the best of charity is from a position of wealth, and the upper hand is better than the lower hand, and start with those you support' in Sahih Muslim 2: 717. And from Abu Sa'id, he said: 'Pay Zakat al-Fitr as a sa' of dates or a sa' of barley or half a sa' of wheat or he said grain for every person, young or old, male or female, free or owned, if wealthy' in Sharh Ma'ani al-Athar 2: 45. And from Abu Huraira, he said: 'Zakat al-Fitr is for every free and slave, male or female, young or old, if wealthy' in Sharh Ma'ani al-Athar 2: 45. See: Al-Badai 2: 70, and Al-Waqaya p. 229, and Allah knows best.