Yahya related to me from Malik from Nafi from Abdullah ibn Umarthat the Messenger of Allah, may Allah bless him and grant him peace,said, "The people of Madina should enter ihram at Dhu'l-Hulayfa, thepeople of Syria should do so at al-Juhfa, and the people of Najdshould do so at Qarn."Abdullah ibn Umar added, "I have heardthat the Messenger of Allah, may Allah bless him and grant him peace,said, 'The people of Yemen should enter ihram at Yalamlam.' "
USC-MSA web (English) reference: Book 20, Hadith 22
Arabic reference: Book 20, Hadith 731