A man asked the Prophet ﷺ from where he should enter into the state of ihram. He replied, "The people of Medina enter ihram from Dhul Hulayfah, the people of Sham from al-Juhfah, the people of Yemen from Yalamlam, and the people of Najd from Qarn."Ibn Umar said, "And the people determined Dhat Irq by analogy with Qarn."
حدثنا هشيم أخبرنا يحيى بن سعيد وعبيد الله بن عمر وابن عون وغير واحد عن نافع
أن رجلا سأل النبي ﷺ من أين يحرم قال مهل أهل المدينة من ذي الحليفة ومهل أهل الشام من الجحفة ومهل أهل اليمن من يلملم ومهل أهل نجد من قرن وقال ابن عمر وقاس الناس ذات عرق بقرن
Its chain of transmission is sahih. Bukhari and Muslim and others narrated it, as in Muntaqa 2344, and Malik narrated it 1:306–307, except that Ibn Umar's statement, "and the people made analogies..." to the end, is an addition found only in Ahmad, as in Muntaqa. See also what has passed in the Musnad of Ibn Abbas, 2128, 2240, 2272, 3066.