In the narration of Abu al-Harith, he said: “Hospitality is obligatory upon every Muslim, whether he is a city-dweller or another Muslim.” Elsewhere, he said: “Hospitality is obligatory upon all Muslims. Whoever receives a guest must provide him with hospitality.” The distinction between the two cases is that ʿUmar stipulated this obligation for the inhabitants of villages, whereas the reports concerning Muslims are general, as indicated by the saying of the Prophet (Allah bless him and grant him peace): “The guest’s night is an obligatory right.” In another wording: “Hospitality is for three days.”
Hospitality is obligatory upon a Muslim toward both Muslims and disbelievers, because of the general wording of the report. Aḥmad explicitly stated this in the narration of Ḥanbal, who asked him: “If a man receives two guests from among the disbelievers, [what is the ruling]?” He replied: “The Messenger of Allah (Allah bless him and grant him peace) said: ‘The guest’s night is an obligatory right upon every Muslim.’” This indicates that both a Muslim and a polytheist may be hosted. Hospitality is like voluntary charity, in that it may be offered to either a Muslim or a disbeliever. He therefore relied on the general wording of the report, which encompasses both the Muslim and the disbeliever.
If a guest stays with a person and he does not provide him with hospitality, it becomes a debt owed to the guest by the host. Aḥmad stated this explicitly in the narration of Ḥanbal, saying: “When people stay with someone and he does not provide them with hospitality, they may claim it if they wish, or leave it if they wish.”
He was asked: “What amount should be provided for him?” He replied: “Whatever sustains him for three days; one day and one night is an obligatory right.” He was then asked: “If they do not provide him with hospitality, do you think he may take from their property an amount sufficient for his hospitality?” He replied: “He may take nothing without the knowledge of its owners, but he may demand his right from them.” Thus, he explicitly affirmed that he has the right to demand it. This indicates that it is established as a liability upon the host, based on the Prophet’s statement in the hadith of Abū Karīmah: “If he reaches morning in his courtyard, it is a debt the host owes him: if he wishes, he may claim the debt, and if he wishes, he may leave it.”
He prohibited the guest from taking property belonging to one upon whom hospitality is obligatory without that person’s permission, in accordance with his general principle: “If a person is owed a right by another man, and that man refuses to render it, while the creditor has access to property belonging to him, he may not take it without his permission.”
The dhimmi (protected non-Muslim subject) must refrain from anything that causes harm to Muslims or to individual Muslims, whether affecting their property or their lives. These are eight matters: joining forces to fight Muslims; committing fornication with a Muslim woman; having intercourse with her under the pretext of marriage; turning a Muslim away from his religion; committing highway robbery against Muslims; sheltering a spy on behalf of the polytheists—that is, a spy; assisting the polytheists against Muslims by providing intelligence—that is, he must not correspond with the polytheists, giving them information about Muslims; and killing a Muslim man or woman.
Likewise, he must refrain from anything that brings disgrace or detriment upon Islam. These are three matters: speaking improperly of Allah Most High, His Book, His religion, or His Messenger. They must refrain from all these things, regardless of whether the imam stipulates them as conditions or not.