ʿAli ibn Abi Talib (may Allah be pleased with him) reported: “The Messenger of Allah (peace and blessings be upon him) taught me four statements: ‘Allah curses the one who sacrifices for anyone other than Allah; Allah curses the one who curses his parents; Allah curses the one who gives refuge to an offender; and Allah curses the one who alters the boundary markers of the land.’” (1) Reported by Muslim.

Meaning of the key phrases
• “Allah curses …”: when the curse issues from Allah, it means being expelled and cast far from His mercy; when it comes from human beings, it denotes reviling and invoking a prayer against someone.
• “Sacrifices for anyone other than Allah”: whether that be idols, revered saints, the jinn, or anything else.
• “Curses his parents”: this applies to one’s father and mother and, by extension, all ascendants. It includes both cursing them directly and provoking such a curse indirectly—for example, by cursing another person’s parents so that he retaliates in kind.
• “Gives refuge (āwā)”: that is, to shelter and protect.
• “An offender (muḥdithan)”: with a kasra on the dāl it means a criminal; with a fatḥa it refers to an innovated matter in the religion. Sheltering him amounts to approving of him.
• “Alters the boundary markers of the land”: these are the signposts that separate your property from that of your neighbor; altering them includes shifting them forward or backward.

Overall purport of the hadith
The Prophet (peace and blessings be upon him) warns his community against four grave crimes, declaring that Allah will banish from His mercy anyone who commits even one of them:
First: seeking nearness by slaughtering to someone other