Sahih Muslim Book 7, Hadith Number 2664.
Chapter : The place where the pilgrims enter upon the state of Ihram.
Ibn ‘Umar (Allah be pleased with them) reported that the Messenger of Allah (may peace be upon him) had commanded the people of Medina to enter upon the state of Ihram at Dhu’l-Hulaifa; the people of Syria at Juhfa; the people of Najd at Qarn (al-Manazil). ‘Abdullah b. ‘Umar (Allah be pleased with them) said: I was informed that he said that the people of Yemen should enter upon the state of Ihram at Yalamlam.