Musnad Ahmad 5:730

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Sulayman, from Ibrahim al-Taymi, from al-Harith ibn Suwayd, who said: It was said to Ali: "Your Messenger used to single you out with something exclusive, apart from the people in general." He said: "The Messenger of Allah, may Allah bless him and grant him peace, did not single us out with anything that he did not single the people out with, except for something in the scabbard of this sword of mine." He then brought out a scroll containing something regarding the ages of camels, and in it was: "Verily, Medina is a sanctuary from what is between Thawr and 'A'ir. Whoever commits an innovation (hadath) in it, or shelters an innovator (muhdith), then upon him is the curse of Allah, the angels, and all of mankind. Neither a mandatory act (sarf) nor a supererogatory act ('adl) will be accepted from him on the Day of Resurrection. The protection (dhimmah) of the Muslims is one; whoever violates the protection of a Muslim, then upon him is the curse of Allah, the angels, and all of mankind. Neither a mandatory act nor a supererogatory act will be accepted from him on the Day of Resurrection. And whoever takes a client (mawla) without their permission, then upon him is the curse of Allah, the angels, and all of mankind. Neither a mandatory act nor a supererogatory act will be accepted from him on the Day of Resurrection."