Praise be to Allah.
It is not permissible to sell food during the day in Ramadan to someone who it is known or thought most likely will eat it in the daytime, except in the case of someone who is sick or is travelling, and other people with similar excuses. There is no differentiation in that regard between a Muslim and a non-Muslim, because the commandments of Islam are also addressed to non-Muslims, according to the more correct scholarly view. Hence it is not permissible for them to eat during the day in Ramadan, or to help them to do that.
An-Nawawi (may Allah have mercy on him) said: The leading scholars and the majority view is that the commandments of Islam are also addressed to the disbelievers, so silk is forbidden for them just as it is forbidden for the Muslims.
End quote from Sharh Muslim (14/39)
It says in Sharh al-Kawkab al-Muneer (1/500):
The commandments of Islam – such as prayer, zakaah, fasting and so on – are also addressed to the disbelievers, according to Imam Ahmad, ash-Shaafa‘i, the Ash‘aris, Abu Bakr ar-Raazi, al-Karkhi, and according to the view of Maalik as narrated by al-Qaadi ‘Abd al-Wahhaab and Abu’l-Waleed al-Baaji. That is because of the verses that include them, such as the verses in which Allah, may He be exalted, says (interpretation of the meaning):
“O mankind, worship your Lord”
“O My servants, then fear Me”
“And establish prayer and give zakah”
“decreed upon you is fasting”
“And [due] to Allah from the people is a pilgrimage to the House”
[Aal ‘Imraan 3:97]
“O children of Adam…”
“O people of vision”
Among the evidence that the commandments of Islam are also addressed to the disbelievers are the verses in which Allah, may He be exalted, says (interpretation of the meaning):
“[And asking them], ‘What put you into Saqar?’
They will say, ‘We were not of those who prayed,
Nor did we used to feed the poor’”
“And those who do not invoke with Allah another deity or kill the soul which Allah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever should do that will meet a penalty.
Multiplied for him is the punishment on the Day of Resurrection, and he will abide therein humiliated”
Al-Ghazaali (may Allah have mercy on him) said: This verse is about the multiplication of the punishment for the one who combined disbelief, murder and zina (unlawful sexual intercourse), who is not like one who combined disbelief with eating and drinking.
End quote from al-Mustasfa by al-Ghazaali (p. 74)
In al-Mawsoo‘ah al-Fiqhiyyah (35/20) it says: Similarly, Allah, may He be exalted, criticised the people of Shu‘ayb for their disbelief and giving short measure; and he criticised the people of Loot for their disbelief and homosexuality… This is the view of the Shaafa‘is and Hanbalis, according to the correct view, and it is what is implied by the view of Maalik and most of his companions. It is also the view of the Iraqi Hanafi shaykhs. End quote.
A number of scholars have stated that it is forbidden to sell food to a disbeliever during the day in Ramadan.
It says in Nihaayat al-Muhtaaj (3/471): An example of that is an adult, accountable Muslim feeding an adult, accountable disbeliever during the day in Ramadan, or selling him food when he knows or thinks it most likely that he will eat it during the day, as my father (may Allah have mercy on him) stated in his fatwas, because in both cases it will lead to sin and is helping in it, based on the fact that the disbelievers are also required to comply with the commandments of Islam, and this is the more correct view. End quote.
Al-Jamal said in his commentary on Sharh Manhaj at-Tullaab (10/310): Not preventing him from breaking the fast does not mean that it is not forbidden for him to do that, because the commandments of Islam are addressed to him too. Thus our shaykh ar-Ramli ruled in his fatwa that it is haraam for a Muslim to give water to a dhimmi [non-Muslim living under Muslim rule] in Ramadan, whether that is in return for money or otherwise, because by doing so he is helping in sin. End quote.
It says in al-Mawsoo‘ah al-Fiqhiyyah (9/211, 212), under the heading: Selling items that are intended for the commission of unlawful deeds:
The majority (of scholars) are of the view that anything that is intended for unlawful purposes, and any action that will lead to sin, is haraam. So it is not allowed to sell anything that it is known that the purchaser intends to use it for purposes that are not permissible…
Ash-Shirwaani and Ibn Qaasim al-‘Abbaadi stated that it is not permissible for a Muslim to sell food to a disbeliever, if he knows or thinks it most likely that he will eat it during the day in Ramadan, as was also stated in a fatwa by ar-Ramli, who said:… Because that is helping in sin, based on the fact that the more correct view is that the commandments of Islam are also addressed to the disbelievers.
And Allah knows best.