From Sahih Muslim (Hadith 2807):
Salim b. 'Abdullah b. 'Umar b. al-Khattab (Allah be pleased with them) reported his father as saying:I heard the Messenger of Allah (ﷺ) as saying that the people of Medina should enter upon the state of Ihram at Dhu'l- Hulaifa, the people of Syria at Mahya'a and that is Juhfa, and the people of Najd at Qarn (al-Manazil). 'Abdullah b. 'Umar (Allah be pleased with them) said: (I did not hear it myself from him) but heard from them saying that the Messenger of Allah (ﷺ) had (also) said: The people of Yemen should enter upon the state of Ihram at Yalamlam
Reference: Muslim 2807