Sahih Bukhari Volume 2, Book 26, Hadith Number 600.

Narated By Nafi’ : ‘Abdullah bin ‘Umar said, “Allah’s Apostle said, ‘The people of Medina should assume lhram from Dhul-Hulaifa; the people of Sham from Al-Juhfa; and the people of Najd from Qarn.” And ‘Abdullah added, “I was informed that Allah’s Apostle had said, ‘The people of Yemen should assume Ihram from Yalamlam.'”