or shelters an offender, upon him be the curse of Allah, the angels, and all people. He also said, “O Allah, curse Ri‘l, Dhakwān, and ʿUṣayya—they defied Allah and His Messenger.” These were three Arab tribes.

[Explanation]
These are three categories of people who may be cursed in general terms. As noted earlier, it is not permissible to curse a specific individual, even if he is an unbeliever; one may not say, “O Allah, curse so-and-so,” even if that person is a disbeliever. The permissibility applies only to a general curse.

I have added further hadiths that mention various classes of people; those already cited are sufficient, and the remaining texts will be supplied, Allah willing. Among them is the Prophet’s ﷺ statement: “May Allah curse anyone who sacrifices to anything other than Allah—may Allah curse anyone who sacrifices to anything other than Allah.”

Slaughtering for other than Allah is polytheism, because sacrifice is an act of worship, and when a person directs an act of worship to anyone besides Allah he becomes a polytheist. Allah the Exalted says: “Say, ‘Indeed my prayer, my sacrifice, my living and my dying are for Allah, Lord of all the worlds; He has no partner’” (Q 6:162–163), and He says: “So pray to your Lord and sacrifice” (Q 108:2). Thus, He commanded prayer and sacrifice and made them exclusively for Allah. Just as whoever prays to other than Allah is a polytheist, so too is whoever sacrifices to other than Allah.

This ruling applies when the slaughter is carried out as an act of worship, seeking closeness and veneration. If, however, an animal is slaughtered for someone merely as a gesture of hospitality—such as when a guest arrives and you slaughter an animal so that he may eat—there is no harm in that; indeed, it is something encouraged, in view of the Prophet’s