From Sahih Bukhari (Hadith 1526):
Narrated Ibn `Abbas:Allah's Messenger (ﷺ) had fixed Dhul Hulaifa as the Miqat for the people of Medina; Al-Juhfa for the people of Sham; and Qarn Ul-Manazil for the people of Najd; and Yalamlam for the people of Yemen. So, these (above mentioned) are the Mawaqit for all those living at those places, and besides them for those who come through those places with the intention of performing Hajj and `Umra and whoever lives within these places should assume Ihram from his dwelling place, and similarly the people of Mecca can assume Ihram from Mecca
Reference: Bukhari 1526