Sahih al-bukhari:7306 Chapter: Book 96, Hadith 37

Narrated `Asim: I said to Anas, “Did Allah’s Messenger (ﷺ) make Medina a sanctuary?” He replied, “Yes, (Medina is a
sanctuary from such-and-such place to such-and-such place. It is forbidden to cut its trees, and
whoever innovates an heresy in it or commits a sin therein, will incur the curse of Allah, the angels,
and all the people.” Then Musa bin Anas told me that Anas added, “….. or gives refuge to such an
heretic or a sinner…”